The head of the ASTI is calling for dedicated teachers to teach sex education in secondary schools.
It comes after a leaked Government report found that the current curriculum is outdated and does not deal with issues like pornography, consent and LGBT relationships.
Relationships and Sexuality Education was first introduced in the mid-90s, and while it is compulsory at junior cycle, it is inconsistent across many schools at senior cycle.
ASTI President Breda Lynch said teachers should be trained especially to teach sex education.
Ms Lynch said: "Very often we don't have properly trained, qualified people in this area. Teachers are given it as an add-on to their timetable.
"There is no consistency on it, people are not coming out of college with qualifications in this area, and I do believe this an area that needs to be looked at."