Almost half of gay and bisexual survivors of sexual abuse take more than 10 years to report it, according to research by the Rape Crisis Network of Ireland (RCNI).
A new report also shows that gay victims of sexual abuse are less likely to tell family members about it.
The study of gay people attending Rape Crisis Centres revealed that all lesbian and bisexual women who became pregnant by rape terminated the pregnancy.
Another finding relates to the amount of sexual violence LGB survivors experienced in comparison to heterosexual survivors.
LGB survivors disclosed higher levels of multiple incidents of sexual violence than heterosexual survivors (26% compared to 15%).
In terms of gender, gay and bisexual males disclosed almost twice the levels of rape compared with heterosexual males (63% compared to 34%).
A total of 88 LGB survivors attended Rape Crisis centres in Ireland in 2013, and this amounted to 4% of the service’s users.
The other 96% of service users identified themselves as heterosexual.
Transgender survivors who used the services in 2013 were not included in the statistical analysis due to the numbers being too low to accurately do so.
One in four of LGB survivors first disclosed their attack to a friend compared to 12% of straight survivors, and 28% disclosed to parents or another family member against 39% of heterosexual survivors.
All female lesbian and gay survivors of abuse who became pregnant as a result of rape terminated the pregnancy.
Minister Katherine Zappone, says the report raises important issues for the LGBT community.
She said: "I'm so pleased that this report is coming out, there is some of it that makes me so sad too, obviously, but I think, not unlike other things that are going on for LGBT people, it is just demonstrating that we are normal, we are part of the population.
"What happens to us and what we need to do about it, we need to behave as if we are like everyone else and to go and find that safe place."