The efficacy of a nasopharyngeal tube was evaluated in 44 patients with obstructive sleep apnea syndrome. Twenty-four of these patients underwent repeated polysomnographic studies with the nasopharyngeal tube in place. They had a 62.3 percent decrease in apnea index and a 39.2 percent decrease in disordered breathing events/h. The nasopharyngeal tube was successful in 16 of the 24 patients (66.7 percent efficacy), and overall patient tolerance of the tube was 44.2 percent. The nasopharyngeal tube failures had a higher apnea + hypopnea index, lower SaO2 nadir, and a higher PaCO2 than the nasopharyngeal tube successes. They were also heavier than the successful patients. The nasopharyngeal tube is a useful alternative treatment for patients with OSA syndrome and may be used as an immediate therapeutic modality while the patient loses weight or as an alternative for those patients who fail or cannot tolerate nasal continuous positive airway pressure.