Our study included 42 patients with obstructive sleep apnea (OSAS) confirmed by polysomnography. In these patients we investigated the clinical manifestations, the results of the laboratory examinations, including polysomnography, ORL observations and tests of pulmonary function, as well as the therapeutic results. Our patients presented a serious set of symptoms which included excessive daytime sleepiness, snoring, obesity, cranio-facial abnormalities, systemic hypertension, cardiac arrhythmias, incapacity to work with precocious retirement, marital conflicts and high incidence of accidents, namely traffic accidents. An adequate treatment, mostly with nasal CPAP (continuous positive airway pressure), induced marked relief of the symptoms; some patients had an advantage in surgical treatment and weight reduction. OSAS is a frequent entity, affecting mostly male adults after the 5th decade. The lack of knowledge about this entity and the common social acceptance of some of its cardinal symptoms induces considerable delays in its diagnosis. The severity of the symptoms, the personal and social risks of excessive daytime sleepiness, the cardio-circulatory effects and the risk of sudden death during sleep justify an early diagnosis in order to prevent the severe evolution of the disease. Its complex physiopathology and multiple etiological factors justify a multidisciplinary approach.