Emergency services were called to the scene shortly before 11am on Wednesday after a small tractor with a trailer plunged off the path beside the river Aare into the drink, said Bern cantonal police.
Bern's fire service erected an oil barrier to stop fuel flowing into the Aare – a very clean river known for its vivid green colour in summer.
Two divers were sent down to salvage the submerged tractor.
The driver of the tractor – a maintenance vehicle belonging to the municipal engineering department – was able to get ashore by himself. Slightly injured, he was taken to hospital.
As yet it is not known how his tractor came to fall into the river.
It's not the only tractor accident in recent days.
Last week a tractor fell down a slope in the canton of Obwalden and was left dangling precariously over a motorway.