Half of medical students surveyed say they were bullied or sexually harassed in the past year by more senior medical staff.
The preliminary results of a survey conducted by the Medical Students' Association showed the majority of those who were bullied were reluctant to make a formal complaint for fear of damaging their career.
Almost 300 medical students responded to the survey; 52 percent said they had been sexually harassed or bullied, though only 11 percent said they had reported it to authorities.
Association president Elizabeth Berryman said harassment and racial abuse was happening, and consultants and registrars were the most likely culprits.
"I think it stems from the fact that we have a hierarchy in the medical profession and that we very much work in the apprenticeship model," said Ms Berryman.
"I think that one of the reasons why only 11 percent of people report that they've had bullying to the appropriate channels is that they're afraid of consequences for their future career if they do say that they are being bullied.
Ms Berryman said district health boards and other groups representing medical professionals should take action to ensure the work environment is safe.
A Wellington lawyer with experience in workplace bullying claims said the fear of reprisal often stopped people from officially laying a complaint.
Andrew Scott-Howman said people should speak up because otherwise they were tacitly condoning the behaviour.
"Of course you can imagine the disincentive to doing that is fear of reprisal and what it might mean for your career, particularly if you are the only one and the other 20 people who are suffering from this behaviour simply put their heads down and try and ignore it.
"So there's a real danger that unless people stick together and make complaints together nothing will be done."
The Resident Doctors' Association, a doctors' union, released a separate survey earlier this month which found 600 junior or resident doctors experienced or witnessed inappropriate behaviour over the past two years.
National secretary Deborah Powell said students must not be afraid that they will put their careers in jeopardy by speaking out.