Pained by the loss of a close friend — a former Napa High School classmate — Floyd McGregor knew he had to do something to help combat AIDS.

But he wanted to do more than host a party for friends where awards from a “guess-who-gets-an-Oscar” contest were donated to a local startup organization dealing with the lethal virus’ impact on wine country. He’d done that already.

So, with the encouragement of partner John Cole, in 1989 McGregor enlisted the help of other concerned Napans to stage a major fundraiser — an Academy Awards gala that would turn the spotlight on HIV and also raise money to deal with the toll it was taking here.

On Sunday, the event McGregor launched — the annual Napa Valley Oscars bash — celebrates its 20th anniversary, continuing to raise money for HIV education and clients of Queen of the Valley’s Care Network.

Although medicine is prolonging life, AIDS has not gone away, the earnest McGregor declared. And people living with AIDS are still neighbors in need, he observed.

While McGregor turned the reins of the annual fundraiser over to others years ago, he continues to support the efforts of those who’ve taken his place — those who have planned an elaborate gala at Sterling Vineyards on Sunday night. And he’ll be there, this time as a paying guest, enjoying a special four-course dinner as the Academy Awards event plays out on big screen TVs set up at Sterling Vineyards.

The 20th anniversary event has been underwritten by Diageo, parent company of the wine firm hosting the gala, with a large assist from Ambrosia.com/WTN Services.

Diageo’s largess allowed for reuniting this year the two fundraising efforts built around the annual Oscars telecast — the relatively informal Black T-Shirt Party, chaired by Chris Edwards and Scott Butler, and the Black Tie Dinner Party, chaired by Napa designer Michael Holmes.

Two decades ago, the Oscars bash was launched at the Clarion Hotel (now the Marriott) where it was held in just one of the meeting rooms. The following year, ticket sales were so brisk that the hotel staff had to allocate all of the meeting space to Oscar partyers.

“But we outgrew the Clarion and moved to the Napa fairgrounds,” McGregor recalled. “Eventually, we were attracting 600 to 900 people every year and we had entertainers like RuPaul, Village People and Weather Girl Martha Wash on the bill. It was while we were at the fairgrounds that Michael Holmes started the Black Tie dinner, with the help of a great team of volunteers that had been growing each year.”

In 2000, the Oscars bash moved to the hangars of Japan Air Lines and the tarmac at Napa County Airport, with Holmes transforming the black tie dinner tent into the set of the famous Bergman/Bogart film, “Casablanca.”

Other venues for the annual informal Oscars party have included Embassy Suites, the Napa Valley Opera House and Lincoln Theater. The black tie party has been held in recent years at Copia and Domaine Chandon.

McGregor said he was driven to produce the fundraiser year in and out “because of all the people I kept losing. I guess I felt I could help find a cure for AIDS if I kept at it.”

But he’s quick to point out that he didn’t do it alone. Members of the original committee and those who volunteered on a regular basis included Tom Fuller, Mariah Smith, Sandy Smart, Bruce and Nancy Bradley, Pat Howard, Janet Allenspach, Lynn and Corey Johnson, Ellie Hubbard, Cydney Hanson, Axel Fabre, Tom Ahern, Marghi Hagen, Robin Bezzerides, Gretchen Odders, Richard Carter, Randy and Linda Hodge, Dan Breit, Eric Osterle, and spinning the post-Oscar dance music for all 20 years, deejay Rotten Robbie.

McGregor said he said he called and e-mailed most of the early volunteers and at least a dozen will be attending this year’s Black Tie Dinner.

Asked to recount a few vivid memories from the early days, McGregor recalled how technology was pretty basic two decades ago. He was one of the few who had a computer and printer at home, housed in his bedroom.

“Our deadline was approaching and we didn’t have the silent auction bid sheets done for the party. It was well after midnight and I went to bed. I just remember waking up and wondering who were these strangers in my bedroom.”

The night RuPaul entertained partygoers, McGregor said he was in a cherry picker, above the crowd in Chardonnay Hall. “Looking at everybody and the energy in that room, if gravity hadn’t been holding them down, everybody would have been on the ceiling.”