Roshane Wickramathilake, who has competed in nude Olympics at his university, said posing for New York-based photographer Tunick was "a once in a lifetime " opportunity.
"There is a lot of body dysmorphia. A lot of people don't feel comfortable in their bodies and it's a good way to say 'you should feel comfortable in your own skin' and 'everyone is beautiful'," he told reporters after the shoot.
Mr Wickramathilake hoped with his sister at work, parents overseas and girlfriend sitting an exam they wouldn't see him in the buff.
"I think all the important people involved are away from the TV so I hope it stays that way," he joked.
Up to 400 models gasped and squealed as they laid naked on the cold concrete of the Woolworths car park at Prahran wrapped in a sheer red shroud as part of a mass nude shoot on Monday morning with the temperature hovering around 10 degrees.
Belle Harvey, who previously was a life model, said it was a very respectful shoot and it was "lovely to be connecting with people in a different way".
"No mucking around, quick, to the point. It was good fun," she told reporters about the 15-minute shoot.
"It is a celebration of who we are. We are all different but we are all just people being."
Up to 500 participants were expected to brave wintry conditions for three shoots in the city on Monday with another two on Greville St and at the Bromley Ballroom.
The installations are part of the Provocare Festival in Melbourne's Chapel Street precinct.
