The most important consequence of using chemotherapy for Hodgkin's disease is its cure. Results of the MOPP program, developed at the National Cancer Institute in 1964, indicate that the majority of the 80% of patients who attain complete remission, who are at risk for ten years, have remained disease-free. The presence of symptoms and the histologic subtype, nodular sclerosis, has had important negative influences on prognosis. Review of three long-term adverse consequences of chemotherapy revealed sterility to be the most significant effect of drug treatment in this young population. Adverse effects of the immunosuppressive drugs in MOPP proved to be minimal. The carcinogenic effect of MOPP when used alone was surprisingly small, but increased significantly when combined with irradiation. National mortality from Hodgkin's disease has decreased abruptly since the introduction of effective chemotherapy for Hodgkin's disease in 1970.