The three dozen or so protesters held their protest in the inner courtyard of the museum, where they unfurled banners and chanted slogans in front of tourists queuing up for tickets.
One of the banners read "Peter the First was bisexual."
"We chanted: 'Same-sex marriages without compromise,' 'Equality for gays and lesbians,' 'Homophobia is a national shame,' and 'Homophobia is a disease,'" Maria Yefremenkovo, the rally's organizer, told RFE/RL's Russian Service. "One young man treated us as pederasts, others just watched with some dismay and a few smiled."
Using similar tactics to a gay rights protest in Moscow last month, organizers only revealed the location of the demonstration at the last moment to outwit riot police.
They say the subterfuge was needed to avoid a repeat of the violence that has marred previous attempts to hold Gay Pride parades, when police, nationalists, and ultra-Orthodox believers beat protesters.
The June 26 rally was nonetheless quickly broken up by police and five activists were briefly detained, including Yefremenkovo.
Homosexuality could be punished with prison in Soviet times. Russia has since decriminalized homosexuality but intolerance remains very widespread, with nationalists and ultra-Orthodox believers saying homosexuals should be punished or treated in hospital.
Polls have shown more than 80 percent of Russians regard homosexuality as immoral.
Moscow Mayor Yury Luzhkov has described gay rallies as satanic and vowed not to allow them in his city.
written by Claire Bigg based on RFE/RL's Russian Service and wire reports