Students said the lack of LGBT visibility in school contributed to the high levels of homophobia and transphobia.
Newly published research reveals 67% of LGBT youth in Northern Ireland feel unwelcome at school.
The study shows further evidence that schools are having a negative impact on the emotional well-being of Irish LGBT youth.
Northern Ireland has around 30,000 LGBT young people in their schools.
Focus groups with LGBT youth revealed students found their teachers to be unwilling or unable to adequately educate them about LGBT issues.
They also found trans youth felt that schools do not have an understanding of them or their needs. They feel teachers need to pay more attention to names, pronouns, uniform, toilets and changing facilities.
Students felt a lack of LGBT visibility in their education contributed to the high levels of homophobic and transphobic language they experienced in school.
63.1% of the young people surveyed felted trans issues were handled ‘badly’ or ‘very badly’ by their teacher.
‘Why has it taken 17 months for this report to be published?’
The Department of Education published the research on September 14 despite finishing it in April 2016.
A Northern Ireland LGBT support and advocacy group questioned why they waited so long.
Director of The Rainbow Project, John O’Doherty, said: ‘I, personally have raised these issues with three consecutive education ministers. Despite this, no action has been taken by the Department to address these clearly evidenced inequalities.
‘Additionally, it is clearly marked within the research report that it was completed in April 2016; why then has it taken 17 months for this report to be published?’
He also added: ‘‘We are very disappointed that, contrary to standard practice, the Department specifically commissioned research which was prohibited from including recommendations.
‘With this in mind, we are calling on the Department to immediately outline how they intend to respond to this clearly identified need.’