Sixty consecutive previously untreated adults with surgically confirmed stage IIIA Hodgkin's disease (39 stage IIIA1, 21 stage IIIA2) began therapy at St. Bartholomew's Hospital between 1969 and 1981. Prior to 1973, treatment consisted of total nodal irradiation (TNI). From 1973 until 1978 patients were randomly allocated to receive either TNI or cyclic combination chemotherapy of mustine, vinblastine, prednisolone, and procarbazine (MVPP) as part of a Medical Research Council Trial. Since 1978 treatment has been allocated according to substage, those with stage IIIA1 receiving TNI and those with stage IIIA2 receiving MVPP. Seven patients received "non protocol" therapy (extended mantle radiotherapy in three patients, mantle and MVPP in four patients), and have been excluded from the study. Complete remission was achieved in 48 of 53 patients regardless of substage or therapy. Seven have relapsed, one after MVPP and six after TNI. The predicted freedom-from-relapse after MVPP was 96% compared with 60% after TNI, both at 10 years (p less than 0.01). The relapse pattern was the same for both substages in the group receiving TNI. Although overall survival of patients receiving TNI was identical to that of those receiving MVPP, TNI must be considered inappropriate therapy for stage IIIA Hodgkin's disease if permanent freedom-from-recurrence is the goal.