A sleep apnea syndrome due to upper airway obstruction was diagnosed in 25 adult men (25 to 65 years of age) using nocturnal polygraphic monitoring. Excessive daytime somnolence, hypnagogic hallucinations, and automatic behavior, personality changes with abnormal behavioral outbursts, impotence, morning headaches, abnormal motor activity during sleep, nocturnal enuresis, and high blood pressure should suggest this diagnosis when any of the symptoms are associated with loud snoring. Respiratory monitoring during sleep and nocturnal cardiovascular evaluation bring prognostic information and indications for therapy. Three types of therapeutic trials, namely, diet, medications with or without diet, and surgery have been performed. Only surgery has been beneficial in these cases.