Hollywood actress Sharon Stone and Sex and the City star Kim Cattrall joined several thousand "aliens" clad in feather boas and tight leather pants who descended on Vienna for the annual Life Ball AIDS charity event.
Landing on Planet Life Ball was the theme of this year's event, celebrating the ball's 16th year with imagery of outer space and the concept of embracing the alien.
Despite its sober topic, the AIDS charity is arguably the party of the year, attended by a long list of international celebrities who joined the approximately 4,000-strong partying crowd at Vienna's city hall on Saturday night.
Supermodel Linda Evangelista, singer Elton John and TV actress Rose McGowan were among the guests attending the ball, as 45,000 spectators flocked to the city hall square on the mild evening to watch the fashion show, the event's traditional kick-off.
Strictly adhering to this year's motto Landing on Planet Life Ball, scantily clad aliens in extravagant costumes watched the models - celebrities and professionals - on the Red Ribbon-shaped catwalk showing off designs by lingerie label Agent Provocateur.
"After last year's show by (designers) Heatherette, who played sensually with gay cliches, it is important for us this year to make the dynamics in a male-female relationship a topic," Life Ball organiser Gery Keszler said.
Heterosexuals needed to be more aware of the dangers regarding HIV/AIDS, he said, driving home the evening's message.
"Do it like Samantha, always have a condom with you," Cattrall said at a press conference ahead of the event, referring to her character in the hit TV series, the sexually active Samantha Jones.
Music superstar Mariah Carey, British singer Kelly Osbourne and model Kate Moss had been expected to attend, but apparently changed their minds.
Earlier this month, former US President Bill Clinton scrapped plans to participate in a charity gala preceding the event, citing scheduling difficulties.
Last year, Clinton received a $US1 million ($A1.07 million) donation for his AIDS charity when visiting Vienna ahead of the Life Ball.
Organisers said they hoped to top last year's proceeds of 1.2 million euros ($A1.98 million) for HIV/AIDS charities.
In its 16th year, Keszler's brainchild has established itself as a major society event outclassing Vienna's famous Opera Ball.
