The law legalised the status of gay kiwis.
Prime Minister Helen Clark, speaking at the 90th birthday celebrations for the Labour Part in Manukau, says it was the courage of a small number of politicians, on both sides of the House, that helped push the Act through.
She says their strength gave gay New Zealanders a voice in society.
Miss Clark says the community has come a long way in the last two decades and added to the diverse mix that is modern New Zealand.