Politics came near to overshadowing the glitz as one US host refused to come in protest at an anti-gay law, while the contest's owner, Donald Trump, declared US leaker Edward Snowden, who is living in hiding in Russia, persona non grata.
Tuesday's preliminary round saw participants strut across a stage with a backdrop of onion domes, first in black and red bikinis, and then in sparkling and slinky evening dresses.
The women did not speak except to give their name and country. The biggest cheers went to the Russian contestant as well as those from Mexico and the Philippines, who were greeted by flag-waving fans.
The winner will be crowned at the main show on Saturday, which includes an interview round.
The judges for the main show will include Aerosmith singer Steven Tyler and flamboyant Russian pop king Filipp Kirkorov, while ex-Spice Girls star Mel B will co-host.
The organisers promise the unveiling of a million-dollar "emerald, ruby and diamond" swimming costume on Saturday, which the winner will get to wear.
While hardly a trail-blazer on gender issues, Miss Universe this year has prompted a row on gay rights.
The show's initial co-host Andy Cohen, who is openly gay, pulled out in August because of the choice of Russia as the venue.
He criticised a law passed by Putin in June that bars promoting homosexuality in the presence of minors and has prompted international concern that it can be used to crack down on gay pride events.
However NBC host Thomas Roberts, who is also gay and has married his partner, has taken over the role.
"I choose to offer my support of the LGBT community in Russia by going to Moscow and hosting this event as a journalist, an anchor and a man who happens to be gay," he said in a statement, while calling Russia's treatment of gay people "unacceptable".
Miss USA, Erin Brady, said she understood why Cohen pulled out.
"I think a lot of people had mixed emotions coming here. If that's something he believed in and he didn't feel comfortable, then I support that," she told AFP.
But she said that Roberts "had a different outlook on it, he thought: well you know what, I want to come here and show people that it's OK."
The show's billionaire owner Trump took to Twitter last month to bar National Security Agency leaker Snowden from attending the show.
"Message to Edward Snowden, you're banned from @MissUniverse. Unless you want me to take you back home to face justice!" he wrote.
Snowden is believed to be living in or near Moscow after leaving its Sheremetyevo airport for a secret address in August.
Trump issued an invitation to Putin, however, telling NBC in October that: "We have invited Vladimir Putin and I know for a fact that he wants very much to come."
"It would be beautiful to have him there and I would be honoured to meet him," said Miss USA Brady.
The contest began in Palm Beach in 1952 and still bans its contestants from being married or pregnant. Complete with swimsuit round, the contest remains hugely popular, particularly in Central and South America.
Widely tipped to take the crown this year is Miss Philippines, 24-year-old chemistry graduate, Ariella Arida.
Russia won Miss Universe in 2002, but the policewoman Oksana Fyodorova was dethroned after US shock jock Howard Stern provoked her into chatting about her sex life. She now presents a children's television show.
The show is being held in Crocus City Hall, a concert venue by the Moscow ring road. Performing at the show will be pop singer Emin Agalarov, whose family company built the venue. He has made a video with the current Miss Universe, American Olivia Culpo.
The singer, known as Emin, is also the son-in-law of the President of Azerbaijan, Ilham Aliyev, and performed at the Eurovision song contest when it was held in Baku last year.