An upbeat and mainly young crowd, including students, families with young children, and couples gathered outside in the cold to show their support for Eva Prewein and Anastasia Lopez, who were barred from the cafe after greeting and kissing each other when they met for a tea there last week.
They told the crowds at the protest that they were not doing anything provocative, like having a long snog, but just doing what many other, heterosexual couples would do when they greeted one another.
But a waiter refused to serve the girls for more than two hours and then the manager barred them when they kicked up a fuss.
Lopez recounted how Christl Sedlar, manager of the cafe on Vienna's famous Ringstrasse boulevard, informed the outraged pair that "diversity such as this belongs in a brothel, not in a traditional coffee house".
On Friday evening the 112-year-old cafe was closed and police guarded the door - although someone had managed to spray the words “smash homophobia” on the wall earlier in the day.
On Thursday Sedlar had apologized for her actions - saying that she “overreacted” - but that didn’t stop thousands pledging their support and attendance for the gathering on Facebook.
Dunkin' Donuts seized the opportunity for some free marketing by giving away heart shaped doughnuts to any of the assembled couples who kissed each other during the protest.
An acapella choir sang Depeche Mode songs and Lopez and Prewein called on the cheering crowds to stand up for others when they see someone being discriminated against or treated badly.
They said they felt deeply hurt that none of the customers at the cafe came to their defence, and that it was still unusual to see gay couples holding hands on the streets of Vienna.
Representatives from political parties including the Greens, the Neos and the Social Democrats called for more tolerance and respect in Austria and stressed that gay couples should feel free to express love and affection openly, just as heterosexuals do.
Ulrike Lunacek, Austria’s Green MEP who is openly gay, told the crowd that heterosexual couples are not thrown out of Vienna’s cafes for kissing, and gay couples shouldn’t be either.
She added that it is important that Europeans make a stand against homophobia, in a world where gay people can still be sentenced to death for their sexual orientation.
Julia and her partner Matthias, there with their one-year-old son, told The Local that they wanted to show support for a more tolerant society, and give a sign that Vienna is a modern world city where people shouldn't fear discrimination.
Vienna's younger generation seems all in favour of tolerance