Swiss voters have backed same-sex marriage in a referendum, according to projections.
More than 60% supported the measure, which would bring the country into line with most of western Europe.
In the build up to the vote, church groups and conservative political parties opposed the idea, saying it would undermine the traditional family.
Switzerland has allowed same-sex couples to register partnerships since 2007, but some rights are restricted.
The measure will make it possible for same-sex couples to adopt unrelated children and for married lesbian couples to have children through sperm donation.
Over the last 20 years most countries in western Europe have recognised same-sex marriage but in Switzerland big decisions go to a nationwide ballot.
The BBC’s Imogen Foulkes in Geneva says this makes social change notoriously slow.
Polls closed at 12:00 local time (10:00 GMT) and full results are expected in several hours.