Amyotrophic lateral sclerosis (ALS) is a disease involving motor neurons. There are two major problems in anesthetic management for patients with motor neuron diseases; prolongation of the effect of non-depolarizing muscle relaxant, and controversy about a use of neuraxial block. We describe the anesthetic management of laparotomy for a patient with ALS by general anesthesia alone. A 55-year-old man, suffering from ALS, was scheduled for hemicolectomy and colostomy. General anesthesia was induced by intravenous administration of ketamine, thiopental and fentanyl. After manual ventilation using sevoflurane (5% in oxygen) for 15 minutes, the trachea was intubated without using a non-depolarizing muscle relaxant. General anesthesia was maintained by sevoflurane, nitrous oxide and fentanyl. Since muscle relaxation required for tracheal intubation and surgical procedure was obtained sufficiently using sevoflurane, a non-depolarizing muscle relaxant was not necessary throughout the anesthetic management. The patient emerged from general anesthesia smoothly, and was extubated without any complications. For the postoperative pain management, we administered opioids intravenously, providing good analgesia. The postoperative course was uneventful, and there was no exacerbation of neurological signs and symptoms of ALS.