Case report of an obese patient who suffered a bilateral rhabdomyolysis after major abdominal surgery under general anaesthesia combined with thoracic epidural analgesia. The patient was in the lithotomy position during the ten hours time period of the surgery. As the patient was sedated in the intensive care unit, the diagnosis was made more difficult. Clinical signs consisted of pain, oedema and neurosensitive deficit in both legs. Creatinine kinase plasma concentration was increased. Treatment included fluid infusions and fasciotomy. The sequelae were major and consisted mainly in muscular deficiency of both legs. This complication is favoured by prolonged surgery and muscular compression elicited by non physiological positions.