Three in four trainee and newly-qualified teachers have already considered leaving the profession, according to a poll.
More than half suggested that they do not think they will still be in teaching in 10 years time, while one in four think they will be out of the classroom in just five.
The survey, conducted by the Association of Teachers and Lecturers (ATL), questioned almost 900 students and new teachers about their views on teaching.
Overall, the vast majority (79%) said that they do not feel like they have a good work-life balance.
And 73% said that they have considered leaving the profession.
The top three reasons for this were: because of their workload (76%), "teacher bashing" in the press and a lack of respect for the profession (30%) and an increasing expectation to take part in out of hours activities.
Around 54% said they did not think they would still be in teaching in 10 years time, and 24% did not think they would be in five years time.
One third-year trainee primary teacher in Bedfordshire told researchers: "My peers and I are often told to be prepared to be disappointed, stressed, and to quit. There is very little positivity in the profession at the moment. Teachers feel undermined and unappreciated. I think teachers are concerned for those coming into the profession as they don't wish for others to be as stressed and disillusioned as they are."
Those surveyed were also asked what they enjoy most about being a teacher. The top answers were: when a pupil has a "lightbulb" moment (79%) and helping children to enjoy what they are learning (76%).
Eight in 10 said that they wanted to become a teacher because they like working with young people, while 75% said that they wanted to make a difference and 57% like the idea of variety and every day being different.
ATL general secretary Dr Mary Bousted said: "New teachers, like their more experienced colleagues, are enthusiastic and caring professionals who want time to do their job well and have a reasonable work-life balance.
"It's incredibly sad to hear that so many are already disillusioned so early on in their careers, but it is understandable given the pressure and stress of a high workload."
:: The poll questioned 889 trainee and student teachers and newly qualified teachers in England between November and January.
A Department for Education spokeswoman said: " Teaching continues to be a hugely popular career with more teachers in England's classrooms than ever before. We want to attract the best and brightest graduates into teaching - and keep them there. Our statistics show that three-quarters of teachers were still in their post five years after qualifying.
"However, we recognise the issues our hard-working teachers face. The Secretary of State has made clear to the teaching unions our commitment to working with them to help reduce unnecessarily high workloads, caused by needless bureaucracy."