The development of chylothorax and chylopericardium are serious and often life-threatening clinical entity. The ideal treatment of these problems is not well established to date. We reviewed our experiences with chylothorax or chylopericardium in 16 patients [17 cases] from July 1979 to May 1989. Ages ranged from 20 days to 41 years. The etiologies were traumatic in 10, congenital or idiopathic in 5, and tuberculous lymphadenopathy in one. In 8 patients, the chylothorax or chylopericardium occurred as a complication of cardiothoracic surgery. Eleven patients were treated nonoperatively with either repeated thoracenteses or chest tube drainage. Five patients underwent operative treatment: transthoracic thoracic duct ligation [three patients], thoracic duct ligation combined with decortication [one], and oversewn the defect of mediastinal pleura[one]. Duration of preoperative therapy ranged from 18 to 38 days. One of eleven [9.1 %] patients treated nonoperatively died. Of the surgically treated group, there were no deaths. All patients except one dead cured or improved either treated nonoperatively or operatively. Our experience suggests that surgical management of the chylothorax or chylopericardium is not always required, and each patient must be judged individually according to disease process.