Histopathological findings in the liver in a series of autopsies on 110 patients suffering from leukaemia or lymphoma were reviewed. No treatment had been given to 23 patients, 50 had received chemotherapy alone, 23 chemo- and radiotherapy and 14 underwent bone marrow transplantation. The 23 untreated patients showed neoplastic infiltration in 10 (44%) and fibrosis in 16 cases (70%). The 14 bone marrow recipients showed mainly acute necrosis, zonal in six (43%) and focal in one (7%), and cholestasis in five (36%), together with marked siderosis in 11 (79%). Patients receiving chemotherapy or chemo-/radiotherapy showed similar changes consisting of neoplastic infiltration in 14 (28%) and in five (22%) cases respectively, and fibrosis in 31 (62%) and 17 (74%) cases respectively. Steatosis was seen in 70% of cases in the chemo-/radiotherapy group and in 50% of cases in the other groups. Infections were seen in all groups, particularly in the chemotherapy group (four fungal and two bacterial including one tuberculosis) and in the chemo-/radiotherapy group (one fungal and one bacterial). Cytomegalovirus infection was seen only in the bone marrow transplant group.