Sleep apnea occurring in association with neurologic lesions is usually of the central type. We have described a patient in whom obstructive sleep apnea followed a lateral medullary syndrome. We hypothesize that the upper airway obstruction during sleep was due to weakness of the palatal and pharyngeal muscles resulting from the neurologic lesion. The patient initially had reduced respiratory center motor output (mouth occlusion pressure) which increased significantly after tracheostomy. We conclude that obstructive as well as central apnea may follow neurologic lesions. Each patient should be carefully evaluated to provide proper treatment.