Delayed skin test responses to several or all of a battery of six antigens were evaluated in 64 patients with disseminated Hodgkin's disease before, during, and after multiple-agent chemotherapy. Before therapy, 53% of patients had one or more positive skin tests, as compared to 55% during intensive chemotherapy, 79% during maintenance therapy, and 100% after discontinuation of all treatment. Pretreatment skin tests were of no value in predicting clinical response to chemotherapy. Response rates, duration of response, and survival were similar among anergic patients and patients with positive skin tests before treatment. There were too few patients who remained anergic after intensive induction chemotherapy to permit a correlation of immunologic reactivity with course. We conclude that skin test responses to recall antigens, before or during aggressive treatment, are more indicative of Hodgkin's disease activity (and also, of the immunosuppressive effects of treatment routines) than of prognosis.