Volunteers who fought along the Republicans in the Spanish Civil War have been rehabilitated by parliament.
The Senate on Thursday unanimously followed the House of Representatives in lifting the convictions of those who served in a foreign army in the 1930s.
Up to 800 Swiss-based volunteers, including a small number of women, joined Republican troops fighting against fascist rebels. More than 400 of them were handed jail sentences.
Only a handful of veterans are still alive.
Switzerland is one of the last countries to rehabilitate the volunteers who have appealed for recognition of their fight for democracy.
Critics argued clearing the names was tantamount to re-writing history.
Justice Minister Eveline Widmer-Schlumpf told the Senate the pardon was justified from today's point of view.