Half of the graduates taking part in a government-backed programme to give students a taste of life in the classroom will remain in teaching.
Others completing the Teach First programme, which offers a two-year stint in a disadvantaged London school, will enter careers in business instead.
Brett Wigdortz, Teach First's chief executive, insisted he was pleased with the result and said the charity had not set itself a target when it launched the programme.
He said: "Of the half leaving, most of them are going into the business world, joining companies like Barclays or HSBC. But I don't think it is because they are disillusioned, and I would still say that the programme has been a success."
The Government, which pays pound;2,000 to schools that accept trainees in the first year, was keen to back Teach First, an independent charity, whose aim to turn graduates into inspirational teachers is based on the highly successful Teach for America.
Gordon Brown announced in his March Budget that the programme, regarded as a cost-effective route into teaching, will be rolled out to five other cities, starting with Manchester in 2006. The course also enables participants to gain other qualifications, including a business leadership certificate.
The Department for Education and Skills refused to comment on the retention rate. However a spokesman confirmed that "teacher wastage" overall for the year 2002-03 was 8.9 per cent.
When Teach First was launched in 2002, the then-education minister Stephen Twigg said the programme "could make a real difference for schools, graduates and business".
A spokesman for the scheme said: "This scheme encourages people who would never think about teaching to go into it for two years and then, should they wish, take their experiences of teaching into the business community, building up a network of leadership."
Mr Wigdortz said: "We had no targets at all on how many of them would stay in their schools. Our mission wasn't to keep them in teaching as a career, but for them to qualify. Ninety per cent of them stayed for the full two years. From talking to headteachers in these schools, that is a much higher retention rate than normal.
"All of the graduates of the programme have qualified teacher status and I imagine that they will spend some time back in the classroom. But if they were all off to leafy schools, that wouldn't help our mission at all."
Mr Wigdortz insisted that the graduates had all promised to stay in touch with the scheme and were likely to "stay involved helping pupils in challenging circumstances".