We report two cases of patients diagnosed of motoneuron disease. First patient had amyotrophic lateral sclerosis with bulbar involvement and developed prolonged apnea after general anesthesia for elective hemorrhoidectomy. Second patient had Kugelberg-Welander disease or type III hereditary mononeuron disease, underwent laparotomy and had no anesthetic complications. Patients with motoneuron disease should be considered as high anesthetic risk patients because they may develop respiratory complications accordingly to their previous muscle involvement so neurologic and respiratory assessment is basic. The use of succinylcholine should be limited to cases in whom external denervation and muscle atrophy may be ruled out. Short half-life muscle relaxants such as atracurium and vecuronium are advised with monitoring of neuromuscular function. Currently, local-regional techniques are not contraindicated.