The Education Review Office says too many new teachers feel poorly prepared for their jobs.
In a report published on Monday, the review office said 60 percent of the principals it interviewed said their new teachers were not ready.
The report also found graduates from some universities felt better prepared than others, as did those from courses that involved more time in the classroom.
It called for an exit exam for graduating teachers, higher entry standards, and a push to attract the most academically able students.
It also recommended the Teaching Council review the effectiveness of different teaching courses.
ERO's Education Evaluation Centre head Ruth Shinoda said some new teachers were unprepared in key areas.
"Concerningly, we have found that new teachers are not prepared in key areas that really matter.
"For example, over a third of teachers said they were not able to manage classroom behaviour when they started in the role and a third of new primary school teachers said they were unprepared to teach science.
"We are particularly concerned that there is so much variation in the quality of teacher education across New Zealand.
"Some courses are setting up teachers well, but we need all courses to do this. ERO has found that over a quarter of new teachers say their teacher education was ineffective."
The report recommended ensuring teacher education programmes included more of the knowledge and skills teachers need in the classroom.
It said they should better prepare teachers to adapt their teaching to different students, use assessment, work with parents and whānau, and manage challenging behaviour.
The report said teachers who had achieved an excellence endorsement in NCEA Level 3 when they were at school were twice as likely to stay in teaching for five years or longer.
It also found Māori teachers were more likely to feel ready to manage classroom behaviour and more likely to stay in the role.
The report said half of the new primary teachers it surveyed were on fixed-term contracts in their first year of work.
It said they needed greater stability and the Education Ministry should consider guaranteeing employment for newly graduated teachers working toward full registration.
