Bilateral trephine bone marrow biopsies of 370 patients with Hodgkin's disease first seen at the Institute of Hematology, University of Rome, between 1970 and 1981, revealed tumor involvement of the bone marrow in 18 cases. The histologic type was mixed cellularity in 7 cases, lymphocytic depletion in 4 cases, nodular sclerosis in 4 cases, and lymphocytic prevalence in 1 case. Anemia with less than 10 g/dl of hemoglobin was observed in 5 patients; white blood cells were less than 4.0 X 10(9)/liter in 2 patients; platelets were less than 12.0 X 10(9)/liter in 1 case; a pancytopenic condition was observed in only 1 case. B symptoms were present in 14 of the 18 patients. All patients who underwent laparosplenectomy presented spleen involvement, 4 also had liver involvement. All patients were treated with chemotherapy; MOPP regimen was employed in 11 cases, ABVD in 5 patients, and PROVECIP in 1 case. Of the 13 patients evaluable for therapeutic response, 11 achieved complete remission, with a median actuarial relapse-free survival of 15 months. The actuarial survival curve showed that 50% of all patients are projected alive at 47 months with a follow-up ranging from 1 to 109 months.