Liver injury is a frequent, serious complication of allogeneic hematopoietic cell transplantation (HCT) following myeloablative preparative regimens. We sought to determine the frequency and severity of hepatic injury after nonmyeloablative conditioning and its relationship to outcomes. One hundred ninety-three consecutive patients who received 2 Gy total body irradiation with or without fludarabine were evaluated for end points related to liver injury. Patients with diseases treatable by HCT who were ineligible for conventional myeloablative allogeneic HCT because of advanced age and/or comorbid conditions were included. Fifty-one patients (26%) developed hyperbilirubinemia of 68.4 microM (4 mg/dL) or greater, most commonly resulting from cholestasis due to graft-versus-host disease (GVHD) or sepsis. Pretransplantation factors associated with liver dysfunction were a diagnosis of aggressive malignancy (hazard ratio [HR] 1.9; P =.04) and the inclusion of fludarabine in the conditioning regimen (HR 1.8; P =.07). Overall survival at 1 year was superior for patients who had maximal serum bilirubin levels in the normal (78%) or minimally elevated (22.23-66.69 microM [1.3-3.9 mg/dL]) ranges (69%) compared with those in the 68.4 to 117.99 microM (4-6.9 mg/dL; 20%), 119.7 to 169.29 microM (7.0-9.9 mg/dL; 17%), and 171.0 microM (10 mg/dL; 19%) or greater groups. In summary, significant jaundice occurred in 26% of patients and was predominantly due to cholestasis resulting from GVHD and/or sepsis. Aggressive malignancies (mainly advanced disease) and later development of jaundice after transplantation predicted inferior survival.