A NUMBER of Washington-area parents are looking for a more international education, and a more academically demanding one, for their children than most schools can offer. Often these parents are diplomats or work for international agencies. But some, like Peggy MacGregor, are just "looking for something different from a good private school."

McGregor's three children, ages 14, 11 and 8, attend Washington International School. Mrs. MacGregor, who is Japanese, and her husband R. Bruce, who is Scottish and a partner in an accounting firm, were "particularly excited" by W.I.S.'s curriculum, which is designed to give all students a working knowledge of two "internationally significant" languages: usually English plus either German, French or Spanish.

The MacGregors are among those parents whose search for a school is based on definite ideas about what constitutes a complete education. For some parents, that includes preserving a native language and culture. Eiko Miura Kim is Japanese and her husband Oh-Kil Kim, a chemist with the Naval Research Laboratory, is Korean. "My husband took his PhD in Japan, and his Japanese is almost better than mine," says Mrs. Kim. "So we speak Japanese at home with the children." But Oh-Kil Kim is concerned that his children may lose touch with their Korean heritage, so he has enrolled their son Jin, 13, in the Korean School, which meets in a rented Rockville church each Saturday morning and teaches Korean and other elements of the culture.

Parents with practical concerns about their children's educations also include Americans in the foreign service or international agencies. Their offspring may attend school here for a few years, then move on to a series of overseas capitals. For this reason, many of the American-born students at the French School, who constitute about 15 percent of the student body, are from the State Department families. "They have discovered that the French government has a pretty good network of schools abroad and the curriculum is the same in all of them," explains J. F. Bouet, principal. "It's a good way to establish continuity in your children's schooling, wherever you go."

The children of foreign embassy officials and corporate representatives must be prepared to re-enter their native schools when a parent's Washington assignment ends. Horst Siebert has been an economics correspondent in Washington for the German daily Die Welt since 1975. Says his wife, Helga, "We didn't know then and still don't know how long we will be here." To be sure their two children, now in 10th and 12th grades, were prepared for a possible return to Germany, Mrs. Siebert said, "We felt the only fair thing would be for them to go to the German School." There, the curriculum is based on schools in the Federal Republic of Germany and leads to the German university entrance exam, as well as a U.S. high school diploma.

One reason for the many national and international schools in Washington is, of course, the city's large international community. But perhaps another reason the schools are well received by many foreign and American-born parents and children is what Dorothy B. Goodman, director of the Washington International School since she co-founded it in 1966, calls a "general decline in academic instruction" in U.S. education. In the last several decades, languages, mathematics, history and science have been de-emphasized. And compared with other countries, a U.S. high school diploma, she says, "is at least one full year below" the standard of other countries.

Georg Gosse, director of the German School, puts it another way: "There are basic differences . . . for example, the American high school tends to prepare young people for social life. There is a lot of emphasis on children expressing themselves and getting along with others, which I would say is neglected by our rather demanding academic curriculum."

The German School was founded in 1961 to assure that children of Germans serving with the German embassy or international agencies could re-enter their native schools without difficulty at the end of their parents' tour of duty.

At the large, modern facility, built in Potomac in the mid-'70s, all 718 students study German and English; French is required from grades seven to 11, and Latin begins in ninth grade. All teaching is in German, except history, English and physical education. "German is the language of the classroom," Gosse says, "but I must admit it's not the language of breaks and spare time." There, the children lapse easily into English.

About three-fourths of the school's budget comes from the German government, and about half the teachers formerly taught in West Germany's public schools. German books and periodicals are used abundantly in the classroom. Such nationalism in national schools abroad, while intended to guarantee the continuation of the child's education, is sometimes criticized as overly narrow. But Gosse says the philosophy of the German School in Washington has been changing over the last years. "We're using the school more as an international meeting place. For this reason, we're very much interested in American students." The student body reflects this trend toward cultural exchange: it is divided almost evenly between Germans and non-Germans.

Ann Hodgson, 19, who graduates this spring from the German School, falls in between: her mother was born in Germany, her father in the U.S. Anne, who intends to study urban planning at a German university, has attended the school since third grade, when she switched from parochial school.

Her father, James Hodgson, a computer scientist who did graduate work in medieval history, had firm ideas about how his children should be educated. "I am convinced that a classical and mathematical education is the key to higher intellectual activity," says Hodgson. He sent his four sons to St. Anselm's Abby School in Washington and felt the German School would offer his daughter an equivalent curriculum. The school's emphasis on language was also attractive, since Anne had been studying Latin from first grade with her father and was already fluent in English as well as German, which is spoken at home.

Anne remembers that, to gain entry back in 1968, she required a summer tutor in German. "Compared with my previous school, the classes were much advanced in mathematics and some other subjects. But I remember I thought the working atmosphere was very good."

The atmosphere is also somewhat pressured, she adds, and volunteers that she flunked 11th grade due to academic demands as well as personal, adolescent problems. Helga Siebert, who chairs the school's Parents Council, says that "as a parent, sometimes I wish they would have more free time." But she adds that her sons to manage to find the hours necessary to be very active in the school's sports program.

J. F. Bouet, principal of the French International School, describes French education as "very academic and demanding." There are few sports and almost no electives or social and extra-curricular activities. At the three-building Bethesda complex, all instruction, except language classes, is in French; English and one other language are compulsory. The children also study a curriculum heavy with mathematics, history and science. French children comprise aobut half the school's 835 students; the remainder, with the exception of a sizeable block of American students, came mainly from French-speaking countries.

French schools are not as heavily subsidized by their government as are some national schools abroad. Washington's French International School is "fully recognized by the French authorities and we do benefit from some subsidy," explain Bouet. "When we bought the building on Yuma Street [where the school was located until 1975], we got some help. And we get assistance in the form of teachers from the French Ministry of Cultural Affairs."

This worldwide system of French schools recognized by the French Ministry of Education appeals to French and non-French diplomatic families for the educational continuity it offers their children. Children who transfer from one recognized school automatically are accepted into other schools in the network, according to Bouet.

While not large enough to support a full-time national school, the Japanese population of Washington has access to The Japanese School, which meets every Saturday at Georgetown Preparatory School in Rockville. According to Hiroshi Wada, an official at the Japanese embassy and acting principal until the middle of this month, the majority of the 300 students are from Japanese families who are assigned to Washington for several years and will return to Japan. The school's intensive classes in Japanese, math and social studies help these children ease back into their native schools.

The Korean School is organized similarly, but few of its 69 students are fluent in the language since most of their parents are permanent residents here, explain Dr. S. G. Rhee, principal. "These parents primarily are concerned that their children know and appreciate the native language and culture."

Language and culture preservation is also the focus on the full-time Watoto (Swahili for "Children") School. Program director Agyei Akoto describes the school as "Afro-centric." All children study Swahili; eventually, French, Spanish and other languages spoken in Africa will be added. African culture, history and political analysis are an important part of the cirriculum.

At the present time, all 60 children, ages 2 1/2 to 12, entrolled in Watoto are black, and most are American-born. "We are starting to attract some foreign-born children, whose parents are here at Howard, for example," Akoto explains. But Akoto calls the school "still formative," and says that one class is being added each year until the school offers nusrery level to grade 12. The school, located slightly east of Adams-Morgan, is renovating a neighborhood apartment building expected to be ready for classes next month.

Kamili Anderson was already a volunteer at the school when she moved her son Changamire, 4, to Watoto from nursery school. The education he's receiving at Watoto, she believes, is "much deeper. He's understanding more of the significance behind black history, but he's also learning more about current events." Mrs. Anderson and her husband both attended Howard University.

At the Washington International School, the cirriculum, textbooks, teaching staff and students are, by careful design, like a United Nations in microcosm. "Our main thrust," says Dorothy Goodman, "is that education should not be parochial. In every way, we try to be a world school."

At the primary level, students learn reading, writing, math, science, history and geography in two languages. At the middle level, some subjects are taught in one language, some in the other, as one language becomes dominant. All pupils study Latin, literature, math, history, geography and sciences. In their last four years, students continue their demanding regimen, in some cases adding another language. The last two years concentrate on preparation for the International Baccalaureate.

W.I.S. is one of 28 schools nationwide which prepare students for the international university entrance examinations administered by the International Baccalaureate Office, Geneva, Switzerland. The I.B. qualifies students for most of the world's major universities, and for sophomore standing at most North American colleges.

In practice, says Goodman, British or American universities reserve the right to demand certain examinations, grade point levels, even additional course work, for admittance. In most of the rest of the world, however, the national government's recognition of a student's credentials is the determinant. An I.B. will guarantee admittance to the Sorbonne, for example.

The Washington International school's 500 students are divided between two campuses. The younger pupils use the former Phillips School in Georgetown, while older pupils attend classes on the Tregaron Estate, where W.I.S. recently purchased six acres, including the mansion and several other buildings.

Julie Adams, 17, who has been at W.I.S. for the last six years, will receive her I.B. this spring. She has won early admission to Georgetown; she also has applied to Princeton, Brown and Yale. She realized the depth of her feeling for W.I.S. and international education recently, she says, in a discussion with friends. "I suddenly thought: 'What will I do if there's no international school for my kids?'"

Despite the loyalty of most of its students and their parents, W.I.S. continues to struggle with image problems and financial worries. "Some say we're elitist," explains Goodman, "because we're small, academically demanding, . . . and charge fees." Yet, in accord with terms of an early Ford Foundation grant, one-sixth of the children are scholarship students.

But without major grants from the U.S. and other governments or from private foundations, the school must obtain 98 percent of its operating expenses from fees. "Funding has been a source of great sorrow to us. We thought once we proved that this worked, the money would come in."

But Goodman could not be more optimistic about the future of international education and, particularly, the International Baccalaureate. "The idea is spreading like wildfire in North America, because people understand the need . . . in preparing their children for life in the next century."