Sunday's carnival-like event drew gay men, lesbians, cross-dressers and even heterosexual couples - many accompanied by their children - for a mammoth march down skyscraper-lined Avenida Paulista to the beat of loud music blasting from some 20 sound trucks.
Kicking off the parade, Mayor Gilberto Kassab said: "This parade is an opportunity to express our repudiation of homophobia."
Police declined to release a crowd estimate, but organizers hoped the turnout would make it the world's biggest gay pride parade.