We analysed the effect of chemotherapy dose reductions on survival in 35 patients with Hodgkin's disease stage IIIB or IV treated at our institution by three double courses of C-MOPP/ABVD chemotherapy followed by either one further course or by involved-field radiotherapy. Patients receiving reduced doses of alkylating agents had markedly slower responses and worse survival than those not requiring dose reductions. This experience with a very limited number of cases suggests that dose intensity may be an important prognostic factor in advanced Hodgkin's lymphoma, although dose reductions might have been necessary in patients with an intrinsically poor prognosis. Prospective randomized trials comparing standard chemotherapy with intensified protocols supported by hematopoietic growth factors are needed and are being conducted to determine the role of total chemotherapy dose and delivery time in the cure of Hodgkin's disease.