Complications after treatment of Hodgkin's disease are a good model to evaluate the long-term cost of combined chemo- and radiotherapy. Secondary malignancies and mainly acute myelocytic leukemias are the main complications. The 35 of 1,889 cases reported represent increased risk by factor 129. Often preceded by a leukemic phase, they are of poor prognosis. Solid tumors are increased by factor 2.8. They may occur in patients treated by prolonged chemotherapy with alkylating agent without radiotherapy. In seven of 31 patients, solid tumors appeared in the irradiated area. Sterility in young males was present during the first year, though some recuperation was observed thereafter. Better adjustment of treatment to individual risk, to drug sensitivity, and active combinations devoid of alkylating agents are required to reduce the rate of these complications.