In a man in his 60's a colonoscopy and CT scan revealed rectal cancer and cholelithiasis. Laparoscopy-assisted low anterior resection and laparoscopic cholecystectomy was performed；the patient was placed in the 20゜head-down position during the procedure. His left arm was placed along his left side and his right arm was abducted to 60゜.

Shoulder braces were placed over both acromioclavicular joints. The surgery lasted for 6 hours, while the head-down position lasted for 4 hours. After the procedure, the patient complained of left arm palsy. Left brachial plexus palsy was diagnosed from the clinical findings；the palsy symptoms diminished spontaneously within 3 days. Several reports mention neuropathy due to improper positioning during laparoscopic surgery. After this case, we routinely have a discussion with the surgeons, anesthetists and nurses regarding incorrect positioning. We determined the ideal position during surgery to avoid nerve injury due to mal-positioning.