But although 31 percent of women questioned in the Internet poll said they encountered discrimination or unfair treatment at least once a week, things are improving.
"Five years ago, there were a higher frequency of cases where people felt that this was very severe and happening on a daily basis," said Rosemary Haefner, of Web site CareerBuilder.com.
Women in the survey conducted by Harris Interactive felt they did not receive credit for their work, their concerns were not taken seriously, their ideas or input were ignored and they were being overlooked for promotion.
Haefner said managers need to do more to reduce discrimination, she added women employees also have an important role to play.
"Are we being too passive or are we not showing enough confidence in our ideas and communication style. That seems to be something to work towards," she said in an interview.
Nearly half of women who experienced discrimination did not report it because they did not think it would make a difference. They also did not want to be labeled a troublemaker or to lose their jobs.
Most of the women who did report discrimination said they didn't think the claim was taken seriously.
Almost one in five women has felt sexually harassed on the job, but most did not report it. Twenty-five percent of the women who did complain said it was never addressed by the person they confided in.
Haefner said sometimes women simply don't know how to report incidents and that companies need to communicate clearly what their policies are.
"I think the corner office needs to market internally what is (their) approach, what is the company's culture, how do they support that," she said.
Almost one in four women in the poll sponsored by CareerBuilder.com and staffing firm Kelly Services said they felt they have fewer opportunities than male colleagues with the same skills and experience.
Nearly 30 percent believe they are paid less than men. But half of the women questioned in the survey said they had the same pay and opportunities for advancement as their male counterparts.
