French Prime Minister Jean-Marc Ayrault has confirmed to legalize marriage and adoption rights for same-sex couples.
"This is a special parade because it is the first time we have a government, a president, a parliament who are in favor of progress," said Nicolas Gougain, spokesman for the the gay rights group Inter-LGBT.
Organizers were expecting record levels of attendance from the LGBT (lesbian, gay, bisexual, transsexual) community at the parade heading from Montparnasse to the iconic Place de la Bastille.
Symbolically, French Minister for Families Dominique Bertinotti turned out to see the floats set off.
"I go everywhere where the future of the family is at stake," she said, adding that "every bit of social progress benefits society as a whole".
Bertinotti said she was "confident" the law "would be passed in 2013".
Prime Minister Jean-Marc Ayrault said ahead of the march on Friday that "the right to marriage and adoption for all would be put in place" during President Francois Hollande's five-year mandate, but did not specify the date.
The crowd, however, remained skeptical.
"We need to wait and see if these are not just empty promises," said Ludovic, a 25-year-old nurse, wearing a gold wig.
"But it would be good if it does happen so that people who want to get married can."
"We are skeptical about announcements made at Gay Pride," said one woman accompanied by her female partner, both sporting rainbow-colored hats and celebrating their first Pride.
Many considered being given equal status to heterosexuals in the eyes of the law more important that actually getting married.
"It's equality that counts," said French actress and director Zabou Breitman, co-hosting the parade with fellow actor Charles Berling. "They have the choice to say no to marriage."
A number of European nations allow gay marriage, but not France, where only married couples and not civil union partners can adopt.
European nations including Denmark, Finland, Germany, Iceland, the Netherlands, Norway, Spain, Sweden and Britain allow gay adoption.
In neighboring Belgium, gay marriage was legalized in 2003 and adoption in 2005.
But it takes a while for society to change, said Chille Deman, president of the Belgian Gay Pride.
"Laws are extremely important in changing mentalities but change won't come just from that."
Over 80 groups paraded behind the Paris Pride banner that said "2012, equality doesn't wait".
Last year's parade in the French capital drew 36,000 supporters according to police, but organizers claimed the figure was "over half a million".