The retired archbishop was speaking at the launch of a UN-backed campaign in South Africa to promote gay rights.
Archbishop Tutu, 81, is a long-standing campaigner for gay rights.
"I would refuse to go to a homophobic heaven. No, I would say sorry, I mean I would much rather go to the other place," Archbishop Tutu said at the launch of the Free and Equal campaign in Cape Town.
"I would not worship a God who is homophobic and that is how deeply I feel about this."
Archbishop Tutu said the campaign against homophobia was similar to the campaign waged against racism in South Africa.
"I am as passionate about this campaign as I ever was about apartheid. For me, it is at the same level," he added.