Young women in science, technology, engineering and maths are leaving the field because of the gender pay gap and a lack of career advancement.
The 2018 STEM Professions Survey Report released on Sunday found women were under-represented at senior and management levels, leading to gaps of $17,500 in pay despite some companies having gender policies.
Professionals Australia CEO Chris Walton told AAP the gender pay gap was a significant disincentive to women entering or remaining in the STEM professions.
"At a time when we really need the best and the brightest because we have a shortage of skilled people in many areas," he said.
"Outdated attitudes to women taking maternity leave and working part time, often to juggle caring responsibilities, is still stopping us from getting a more equal representation of women in those senior jobs."
Professionals Australia is calling for organisations to work harder on their gender and discrimination policies.
Close to 2000 women in STEM fields took part in the survey, with about half of respondents saying their workplaces did not have policies to promote diversity or deal with discrimination.
In organisations that did have adequate policies, many women said they were not enforced and were "all talk".
A third of female engineers aged between 25 and 35 said they were intending to leave their profession in the next five years.
One respondent says claims of sexual harassment and bullying are not addressed at her organisation as "the boys just look after their friends".
"Current practice where a male in a leadership role is found to be sexually harassing/bullying/discriminating against a team member is to move the team member away from the leader to prevent further detrimental behaviour," she wrote in the survey.
Another respondent is expected to take minutes in meetings even when a junior male colleague is also present.
"I also get asked to do the admin tasks that no other engineer in my team (all others are male) would ever be asked to do," she wrote.
The report's 30 recommendations include linking management performance to diversity and anti-discrimination accountability, gathering and monitoring gender equality data and options for part-time work at senior management levels.
