One in five new teachers quit a high-flying role to work with children and one in 10 is aiming to be a head or deputy, according to a poll.
Many enter teaching hoping to make a difference to people's lives
The Training and Development Agency for Schools said over a third of new maths teachers and 29% of science teachers had given up a managerial post.
The TDA also said 10% of the 893 new teachers questioned were aiming to be a head or deputy head within five years.
However it added that there was still a shortage of teachers in some key areas.
Of those who made the switch into teaching, 79% said they wanted to make a difference to people's lives.
Career switchers had come from various professions.
The poll found that 21% of new maths teachers had an engineering background, 25% of new science teachers were ex-pharmacists or scientists and 32% of modern languages teachers had been administrative or secretarial workers.
Teacher training courses in England and Wales took on 42,000 recruits in 2005 for all education areas.
Of these, 2,058 were training to be maths teachers, 2,998 going to teach science and 1,577 languages.
Josh Beattie, head of teaching information at the TDA, said recruitment for new maths teachers was still running 12% short of its target.
"There is still a need to address this and get people who are able teachers into these areas," he said.
Within the teaching profession about 8% leave the workforce each year. However, Mr Beattie added that about 12,000 also return every year.
Graham Holley, executive director of the TDA, said: "Career switchers bring with them a huge range of highly relevant skills.
"High achievers can reach headteacher status or take on an enhanced classroom role very quickly due to the excellent progression routes in teaching."
He added: "Most importantly, teaching offers the opportunity to work with young people and help to shape their futures."
From September 2005 a newly qualified teacher could expect to start on a salary of at least £19,161. The pay scale for headteachers can rise to over £90,000, depending on the size of school.