The plane came down on Saturday near the village of Tatroz, in the Swiss canton of Fribourg, police said.
They said the victims, who had not yet been identified, were four men and two women. Two bodies were found on the ground and four were in the wreckage.
The single-engine Piper plane had taken off from Belcherette, in the western canton of Vaud around 2.30pm on Saturday.
Witnesses said it overflew Tatroz twice before coming down 100 metres from a farm.