From the standpoint of chemotherapy, the first progress in the treatment of Hodgkin's disease was the identification of the activity of nitrogen mustard in the 1940's. The initial antitumor effect of the drug created a great excitement. However, when all patients later relapsed, there was subsequent dejection and skepticism about the utility of drug therapy. Fortunately, in the 1950's and 1960's, the development of other effective agents (vinca alkaloids, corticosteroids, and methylhydrazines) in conjunction with the elucidation of the principles of combination chemotherapy led to a marked increase in the antitumor response rate of patients with Hodgkin's disease. The value of many of these drug combinations remains under study. Nonetheless, approximately 75% of all patients with advanced Hodgkin's disease treated today with combination chemotherapy can achieve a complete remission. In addition, over half of these remain disease-free long enough to be considered cured. The development of effective treatment, both local (radiotherapy) and systemic (MOPP chemotherapy), has given the clinical investigator the tools to complete, in the 1970's, the therapeutic experiments necessary to refine both the interrelationship between the treatments and their impact upon the natural history of Hodgkin's disease.