The idea sounded like just what was needed for working parents in the Washington area: a training school for nannies.

Northern Virginia Community College, commonly called NOVA, began what was described as the area's first such program last year, enrolling high school graduates and holders of high school equivalency diplomas.

Eighteen months later, the program has produced its first graduates and been pronounced a qualified success, although the supply of nannies is still far outstripped by demand.

Students in NOVA's nanny program are required to attend 50 hours of classes, equal to about one year of attendance, on subjects including child psychology, nutrition, human growth and development, and how to write employment contracts.

At graduation, they get certificates that can be applied for credit toward an associate or undergraduate degree in early childhood education. Some of the graduates will become full-time live-in nannies; others might share child care duties among several families.

The program produced its first graduates in the spring, and all 12 are now employed. Program officials say they know of only two who are nannies; the jobs of the rest are unknown. The program now has national certification from the American Council of Nanny Schools. More than 30 colleges and community colleges have asked NOVA for its curriculum.

"We have encountered some difficulties," said Elizabeth Johns, the college's social science chairwoman. Some students who went to NOVA intending to finish the nanny program switched to the lengthier degree program, which would ultimately allow them to work in a nursery school or day care center, she said.

"They don't want to be confined," Johns explained. "Being a nanny can be very confining" because of the long hours and the necessity to live in.

So the nanny program is recruiting among two special groups: low-income mothers of children in the Head Start program, and teen-aged mothers.

Thirteen students who began the program last Wednesday are mothers of pupils enrolled in Head Start classes in Fairfax County, said Eula Miller, who runs the nanny program. "It's to open up options for those people . . . help them become self-sufficient," she said.

In January, 25 teen-age mothers are expected to enroll under a grant announced Friday from the U.S. Education Department's Fund for the Improvement of Post-Secondary Education. The grant will help pay for counseling and other support services for the young women.

The school's waiting list of parents seeking nannies now numbers 300, Miller said.

"We've got plenty of jobs," she said. "We will never be able to meet that demand."