One in 10 lesbian, gay, and bisexual people have quit a job because of discrimination, while 30% say they have been harassed at work.
The Working It Out diversity report published this morning by GLEN found that many gay people still feel uncomfortable revealing their sexuality to their employer and colleagues.
However, the report found that two out of three people surveyed were open about their sexual orientation at work.
The study was carried out by researchers at Trinity College with support from Ernst and Young.
Ernst and Young director and chair of the LGBT employee network at the company Catherine Vaughan said respondents spoke of stress caused by having to conceal their sexual orientation at work.