Almost four out of five women still believe there is a bias in favour of male staff in the office.
A survey by law firm Peninsula showed 78% of women believe their gender is a barrier to career progression compared to male counterparts.
Eighty-four percent of female employees polled said they have to work harder than male colleagues to prove themselves to their employer.
The poll of more than 2,000 staff also showed that two-thirds of women felt they had been harassed in the workplace by male colleagues.
Government figures have shown that gender bias is still prevalent in UK offices, with women earning 18% less for full-time and 40% less for part-time roles.
Peter Done, managing director of Peninsula, said employers needed to make sure they take positive assertive action to create a company culture which makes it clear discrimination won’t be tolerated or expensive litigation could follow.
“All managers need to be aware of the policies and legislation in place to prevent making discriminatory decisions in relation to the workforce,” he said.
“Tribunals are increasingly looking at written policies and procedures that are created by employers and will almost certainly find an employer to be failing in their duty of care if they do not have a written and well publicised equal opportunities policy.”