Switzerland's highest court has ruled that local authorities can impose fines on people hiking nude in the Alps.
The federal court threw out an appeal by a man who was fined after hiking past a family picnic area with no clothes on.
Judges said the eastern canton (region) of Appenzell had been entitled to uphold a law on public decency.
They said the ban on naked hiking was only a marginal infringement on personal freedom.
Although Switzerland does not have a law against public nudity it does have one against public indecency.
The man had been fined 100 Swiss francs (£69; $109) after he walked naked past a family with small children at a picnic area and a Christian rehabilitation centre for drug users in Appenzell.
"It is not overly high-handed to qualify naked hiking as a breach of decency customs," the court said in a statement.
The BBC's Imogen Foulkes in Geneva says naked hiking is an increasingly popular pastime in Switzerland.
However, Appenzell is a deeply devout and conservative canton - it only granted women the right to vote in 1990 - and the influx of naked hikers has offended many local people, she adds.
The new ruling applies to the entire country.
Naked hikers may now have to look for another country which offers them a warmer welcome, our correspondent says.