Andrew Moffat resigned in December and will leave his post as assistant head teacher at Birmingham's Chilwell Croft Academy later this month.
"In my work I have met with some challenging views from different sections of the community," said Andrew, who has accepted another teaching position at a school outside Birmingham.
"Some Christian and some Muslim parents have told me they don't want their children learning that it's OK to be gay."
Andrew had worked at Chilwell Croft for five years and had trained teachers on how to prevent homophobic bullying.
He had also written a series of books called Challenging Homophobia in Primary Schools (CHIPS), which have been used in literacy lessons for 10 and 11-year-olds across the country, including those at his own school.
One lesson in the CHIPS series describes a picnic at which gay families are present. Pupils are encouraged to treat all the guests equally and not use the word 'gay' as an insult.
Andrew claims the complaints from parents came after he talked to students about his sexuality in an assembly.
"I did come out at school in an assembly after a group of 11-year-olds held up a poster they made, with the heading 'Gay is good,'" he told The Sunday Times. "It seemed like the right time to let the children know that they knew a gay person.
"Following my coming out, some parents from different communities complained to the school, but I maintain that my decision was the right one at that time."
Chilwell Croft School have released the following statement:
"A minority group of parents . . . objected to some of the resource books being used in literacy lessons with some of the oldest children in the school, which explored relationships in different families.
"The . . . objections were primarily voiced by those whose own religion took an opposing stance to homosexuality."
More on Parentdish: Why gay is not an insult
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