Swiss voters have approved a five-year ban on the use of genetically modified crops, final results from Sunday's referendum suggest.
The influential biotechnology industry opposes a ban
A total of 55.7% of the electorate voted in favour of the moratorium across all the country's 26 cantons.
Supporters of the ban include farmers, who believe that the introduction of GM crops would undermine organic produce.
But the biotechnology industry had campaigned against the ban, saying the country must accept new developments.
The BBC's Imogen Foulkes in Berne says the Swiss have long been suspicious of genetically modified crops.
Only one tiny experimental GM crop of wheat has ever been grown on Swiss soil, by scientists at the University of Zurich.
Surveys show Swiss consumers would not buy GM produce.
The EU lifted its own moratorium on GM crops last year.
Switzerland, although not a member of the EU, was under pressure to do the same.