The 54-year-old was part of a group of six tourists from the Netherlands who were hiking along a trail from the Mauvoisin dam to Charmotane.
The accident occurred at an altitude of 2,560 metres when the group reached a snowfield, cantonal police in Valais said in a statement.
The man decided to cross the snow but slipped and fell 200 metres down a gully.
Rescue workers were unable to help. He was found dead on the scene.
After the accident, Valais police and mountain rescue workers warned hikers that despite the high temperatures in Switzerland in recent times, the continued presence of snow in some areas means conditions can still be tricky.