[Lesion of the brachial plexus, caused by wrong positioning during surgery].

We report three patients, which showed plexus palsies after routine operations. Compression and stretch of the nerves despite pads leaded to nerve injury in patient A. Abduction of the arm, fixed wrist, hypotension in steep Trendelenburg position and a preexisting shoulder-arm-syndrome were the causes in patient B. Hyperreclination of the head in semisitting position caused the lesion in patient C. The anaesthetist should know the risks of positioning to prevent nerve injuries.