Avascular necrosis of bone developed in eight patients with advanced Hodgkin's disease who had been treated with combined modality therapy and were in complete remission from their disease. A ninth patient not on protocol but treated with the combined modality program also developed avascular necrosis. The cumulative incidence was 10% among long-term survivors. The etiology is unclear. Prolonged corticosteroid administration has been implicated but usually in much larger doses than the patients in this series received. The possible roles of the other chemotherapeutic agents for Hodgkin's disease, and radiation are discussed. Considerable disability resulted for almost all patients. Three of seven patients primarily with avascular necrosis of the femoral heads had bilateral hip replacements with surgery anticipated in four others. The two patients primarily with humeral head involvement have limited use of their arms. This condition must be added to the known possible serious consequences of combination chemotherapy for Hodgkin's disease. It is uncertain if the frequency of avascular necrosis is higher in patients treated with both radiation and chemotherapy compared with chemotherapy alone. Further studies are needed from other institutions to clarify the frequency and cause of this problem.