More than half of lesbian, gay and bisexual pupils in Scottish secondary schools experience homophobic bullying, according to a new report.
The Stonewall Scotland study also found that a quarter (26%) of them have attempted to take their own life, while more than half (54%) deliberately harm themselves.
Less than a third (31%) said that their school responds quickly to homophobic bullying behaviour.
The organisation is now calling on schools, the Scottish Government, local authorities and Education Scotland to continue working to tackle homophobic bullying.
Stonewall Scotland director Colin Macfarlane said: "The mark of a society is how it treats its young people and so it's unacceptable that over half of gay young Scots face a daily nightmare of homophobic bullying, and deeply worrying that many schools and teachers still fail to challenge it effectively.
"At a time when policy-makers look for ways to boost attainment and raise aspiration, it is deeply disturbing that half of lesbian, gay and bisexual young Scots say they don't feel that they are achieving their best at school.
"We won't rest until every single gay young person in this country can walk through their school gates every morning without fear of being bullied just because of the way they were born."
Almost all (99%) of those surveyed said that they hear homophobic language - like "that's so gay" and "you're so gay", The School Report 2012 found. Fewer than three in five (57%) of lesbian, gay and bisexual pupils in Scotland report that their schools say homophobic bullying is wrong.
Meanwhile almost half (49%) said they do not feel they are achieving their best at school.
The findings are specific to the 158 lesbian, gay and bisexual young Scots aged 12-19 who took part in a national survey of 1,614 young people.