Lesbian and gay couples in Switzerland rejoiced as they legally tied the knot on Friday, when the rich Alpine nation formally joined many other western European countries in allowing same-sex marriage, with some saying better late than never. 

The first same-sex marriages came about nine months after 64.1 per cent of voters backed the "Marriage for All" law in a national referendum. It puts same-sex partners on an equal legal footing with heterosexual couples, including allowing them to adopt children together and to sponsor a spouse for citizenship. 

Switzerland authorised same-sex civil partnerships in 2007. 

Friends and family greeted Aline and Laure - who asked that their surnames not be published - with hugs, cheers, applause and a few joyous tears at a Geneva manor house where they exchanged vows to formalise their two-decade relationship. 

"It's a great joy, a super moment to put in the history books," said Laure, 45, a human resources executive, adding that July 1 holds special importance because it's the 19th anniversary of their civil union. 

Luca Morreale and Stefano Perfetti kiss after converting their registered partnership into a marriage. (Photo / AP) 

"It's normality that's taking effect. It's going to become commonplace, let's say, whether it is two women, two men, or heterosexual couples to marry," Laure said. 

Holding Laure's hand, Aline said: "It's true that Switzerland has been a little slow. It's not a moment too soon, after all. Now's the time." 

With a population of 8.5 million, traditionally conservative Switzerland was until Friday among a few western European nations that didn't recognise same-sex marriages. 

Greece, Italy and the microstates of Andorra, Monaco and San Marino only allow male-female couples to marry. 

Most countries in central and eastern Europe do not allow same-sex marriage.