The EORTC Lymphoma Cooperative Group and the Pierre and Marie Curie Group conducted a multicentre randomised trial on clinical stages IIIB-IV Hodgkin's disease from 1981-1986. Two hundred seven patients were registered and 192 randomised. Actuarial survival at five years for the whole group was 68%. Induction chemotherapy with eight cycles of MOPP resulted in more patients with progressive disease and fewer partial responders than a combination of MOPP and ABVD, for an equal complete remission rate. Half of the partial responders went into complete remission after radiotherapy. At five years there was no significant survival difference between the arms. Progression was recorded in 39 patients of whom only 4 survived. Relapses were most frequent in previously involved unirradiated areas. For 46 relapsed patients, including 21 early relapses within 18 months of start of treatment, the four-year survival rate was 53%. When complete remission was reached, whether early or late with combination chemotherapy or after additional radiotherapy, prognosis was independent of the way in which it was achieved. All efforts should be taken to reach a complete remission for initially progressing patients and for partial responders.