 Melatonin has sedative, hypnotic, analgesic, antiinflammatory, and chronobiologic properties that make it a good premedication agent before anesthesia and surgery. Patients undergoing surgery in our establishment usually receive benzodiazepines as premedicants to reduce anxiety before the surgery. For bariatric patients benzodiazepines are usually avoided due to side effects which could be deleterious in obese patients. 