Veteran Big Gay Out attendee Prime Minister Jacinda Ardern said the day was a chance to celebrate but also a "reminder" of the work to be done for the rainbow community.
Ardern, who has been attending the Ending HIV event at Auckland's Coyle Park for many years, was visiting for the first time as Prime Minister.
"I've lost count of the amount of times I've felt proud to stand on this stage," Ardern said in a speech on the main stage to a cheering audience.
Coming back for the 20th anniversary event as Prime Minister was "very special".
"It is one of many events that shows the incredible diversity of New Zealand, and that is something to be celebrated."
Ardern had planned to attend last year but the festival was cancelled due to heavy rain.
Ardern highlighted the work done to reduce HIV over the past six years, and work the Government had done in the area, including funding the HIV-prevention drug Prep since March last year. They had also lifted the cap on funding for gender assignment surgery.
But while the Big Gay Out was a cause to celebrate, it was also chance to talk about things left to do together.
She highlighted the bill of Labour List MP Marla Lubeck, who was also on stage, seeking to put an end to so-called conversion therapy – a controversial practice which uses psychotherapy to reduce or stop same-sex attraction.
There was also more work to be done to as country to make New Zealand more inclusive.
"As a country we must continue to strive for inclusion, diversity, to ensure LGBTQI community in school, education, work, are in safe spaces. We know as a Government we have work do there, and I can assure you we will keep doing that work.
"In terms of a safe city ... in Phil Goff you have a huge supporter," she said of Auckland's mayor, standing in the audience.
Ardern said she had an announcement to make regarding LGBTQI and mental health, but she would save that for "a little further down the track" for the "mental health-focused budget".
Labour MP Tāmatai Coffey announced during his speech he and his partner Tim Smith were expecting a baby in July.