Catholic education in the region is expanding -- with the Archdiocese of Washington opening its first new elementary school in Montgomery County in a decade and hundreds of students heading to parochial schools under the D.C. voucher program.

In Northern Virginia, two high schools are being planned by the Diocese of Arlington, each to house about 1,000 students within three years.

This growth runs counter to figures that show a 4 percent nationwide decline in Catholic school enrollment in the past decade, most of it occurring recently after increases in the 1990s.

The Archdiocese of Washington, which includes the District and the Maryland counties of Montgomery, Prince George's, Calvert, Charles and St. Mary's, has seen a 13 percent increase at its more than 100 schools in the past 10 years, increasing its enrollment to 33,500 students.

The Diocese of Arlington, now with 42 schools and 17,850 students, reported a 32 percent jump in enrollment and has opened nine elementary schools in the past decade.

Beyond the Washington area's swelling population and strong economic base, Catholic educators attribute their success to a hunger among many families for religious-based values education. Parents also cite the fact that parochial school tuition is a fraction of the cost of top private schools in the region.

"The sense of values tied into the religion was important to me," said Megan Cole, whose two daughters, 7-year-old Molly and 5-year-old Bridget, will attend St. Patrick's Elementary, the Catholic school opening in Rockville this week.

"Public schools teach values as well," Cole said, "but it's not religious-based, and it's important to us."

St. Patrick's Principal Susan Malloy, whose school will open with 40 children in kindergarten through third grade, said many families also appreciate that Catholic schools traditionally have concentrated on reading, writing and arithmetic -- the same academic emphasis written into the federal No Child Left Behind Act for public schools.

"Catholic schools stuck with the basics," Malloy said, in part because they never had "a lot of money to do a lot of experimental education, and we are consistently strong because of it."

Many Catholic schools in the United States were built to cater to immigrant populations that lived largely in cities until the mid-1960s, when a shift to the suburbs created a crisis for the schools; suddenly they found themselves catering to populations that were largely non-Catholic. Today, some inner-city Catholic schools have majority non-Catholic student populations.

Antoinette Peterson is moving her two children from a D.C. public school to Archbishop Carroll High School in Washington this year, even though her family is Baptist. She said she likes the Catholic school's environment and academic rigor.

Her 16-year-old daughter, Thomeisha, said she appreciates the idea of stricter discipline and tough classes. "They do a prayer at the beginning of the day, and you have to take religion class, but you learn about other religions, too," she said. "They aren't going to try to make me Catholic."

Catholic schools in cities such as Chicago are struggling in large part because of changing demographics and because of the rising cost of education, said Michael J. Guerra, president of the National Catholic Education Association, a Washington-based nonprofit group that promotes Catholic education.

Though Catholic education is less expensive than the tuition charged by independent private schools, which can charge $20,000 or more a year, many Catholic schools are located in pockets of middle- and lower-class families, for whom paying even a few thousand dollars is prohibitive, Guerra said.

In the Archdiocese of Washington, tuition generally ranges from $2,500 to $4,000 for elementary schools and nearly $7,000 and up for high schools, said Jennifer Reed, assistant director of communications. Tuition for the new school in Rockville is $6,000.

In the Arlington diocese, which encompasses eight counties and four cities in Northern Virginia, the average tuition is $3,550 for elementary schools and $7,500 for high schools. The tuitions have increased 5 percent to 9 percent annually in recent years, said diocese spokesman Soren Johnson. Much of that is driven by teaching costs; Catholic schools now are mostly staffed by lay instructors, so salaries are much higher than when nuns largely filled the same jobs.

Timothy McNiff, superintendent of Catholic schools in the Diocese of Arlington, said he is concerned about the effect of tuition hikes on families and has taken steps to increase financial aid. The diocese is establishing a $10 million endowment for tuition assistance, he said.

"At some point, the economics comes into play, and it gets too expensive for families," McNiff said.

"And when you get to that point, your identity gets challenged."

That has not stopped the diocese from planning to build two high schools, an unusual step because of the cost; the price tag on each could reach $40 million, said Barry Breen, president of Arlington's Bishop Denis J. O'Connell High School. One school is scheduled to open in Prince William County in 2006, the other in Loudoun County a year later. Each would house 1,000 students, reflecting an enrollment growth in the upper grades.

The economic issue is especially acute in the District, where Catholic educators several years ago created an 11-school Center City Consortium to help schools pool resources and stay open. Half of the families with children in these schools live at or below the poverty level, Reed said.

Patricia Weitzel-O'Neill, superintendent of schools in the Archdiocese of Washington, said that the inner-city schools have slowly been gaining enrollment.

Parochial schools in the District will get a big boost this school year with the arrival of 450 to 600 students -- including Antoinette Peterson's two children -- who were awarded publicly funded vouchers under a $12.1 million program approved by Congress this year. The program provides up to $7,500 for a child to use at a private or parochial D.C. school.

Every Catholic school in the District will take at least one voucher student, and some are taking as many as 13 or 14, though final decisions will not be made until schools begin classes this week, Weitzel-O'Neill said.

Yemi Famuyiwa, left, and children Damisola, 1, and Fisola, 5, visit teacher Cathy Nedlock at the St. Patrick's school in Rockville, the first new Catholic elementary school in Montgomery County in a decade.