A patient with a remote history of Hodgkin's lymphoma was seen with recurring bilateral pleural effusions, finally diagnosed as chylothorax after many thoracenteses. The patient also had a previous history consistent with chylous ascites. The only plausible etiology of the chylous effusions (and ascites) was previous radiation therapy to the chest and abdomen. This cause of nontraumatic chylothorax is unusual and has been described infrequently in the medical literature.