In an ongoing phase II study we are evaluating the role of alpha-2b recombinant interferon in Hodgkin's disease; the study design includes patients with high-risk parameters who are treated by combination chemotherapy MOPP, ABVD, MOPP + ABVD or equivalent combinations. At the end of the therapeutic program which could include also radiotherapy, patients will be randomly assigned to receive alpha-2b interferon at 3 MU/day over 3 months and then 3 MU/three times/week over 9 months or no further treatment. Up to September 1989, 107 patients were randomized; evaluable patients with a minimum follow-up of 3 months are 95, 56 in the arm of interferon and 39 in the arm of no further treatment. The results are preliminary and differences could not be disclosed between the two arms concerning either the relapse rate or the incidence of infections. Tolerance and toxicity due to alpha-2b interferon in patients with Hodgkin's disease could be defined as acceptably good considering that mild and reversible hematological toxicity was experienced in 12 (21%) patients; objective clinical toxicity was recorded in 4 (7%) patients although 7 (12%) patients refused to continue the treatment. Definite conclusions will be drawn when 100 patients per arm become evaluable.