Review of 235 consecutive patients undergoing bone marrow transplantation was performed in order to define the clinical syndrome of venoocclusive disease of the liver (VOD) in these patients. Analysis of all patients with histologically proven VOD revealed a consistent clinical syndrome of liver dysfunction occurring within the first 3 weeks after marrow infusion. This was characterized by hyperbilirubinemia peaking at greater than or equal to 2 mg/dl with at least 2 of 3 other findings: hepatomegaly, ascites, and 5% or greater weight gain. VOD developed in 22% (52 of 235). A persistently elevated aspartate aminotransferase (SGOT) prior to transplant was associated with an increased risk of developing VOD by multivariate analysis (P = 0.0003), and acute leukemia in first remission was associated with a decreased risk (P = 0.02). Neither the preparative regimen (busulfan and cyclophosphamide versus cyclophosphamide and total body irradiation) nor the type of graft (allogeneic versus autologous) influenced the occurrence. Twenty-four of these 52 patients (47%) died with VOD (10% of the entire group). This makes VOD the third leading cause of death in our allogeneic graft recipients, and the second leading cause in our patients receiving autologous transplants. VOD is a common complication of bone marrow transplantation and has a specific clinical presentation, which usually allows diagnosis without the need of liver biopsy.