Up to 10 per cent of high school students are gay, lesbian, bisexual or transsexual, and vulnerable to homophobic bullying, says the Post Primary Teachers' Association.
PPTA president Robin Duff said yesterday that recent research showed New Zealanders who "came out" in their teens were more likely to opt out of higher education because of bullying.
The Lavender Islands study called for teachers and principals to be supportive of the needs of gay and lesbian teens. Duff said: "Many schools are addressing violence and bullying but a major aspect of it - a person's gender and sexuality - is often overlooked."
He added that research showed that students who were bullied often resorted to self-harm.
Teachers were supportive of gay and lesbian students, but needed more support in dealing with issues relating to sexuality.