We reviewed the records of 83 patients who underwent 100 orthotopic liver transplantations in order to determine the following: (1) the methods to predict blood usage, (2) the consequences of an ABO-incompatible transplant, (3) the benefit of providing cytomegalovirus (CMV)-negative blood products to CMV-negative patients receiving a liver from a CMV-negative donor, (4) the association of donor anti-hepatitis B core antigens and subsequent hepatitis B, and (5) the prognostic consequences of rouleaux observed in pretransplant blood compatibility testing. Patient diagnosis, the presence of ascites, a preoperative prothrombin time greater than 15 seconds, and a multifactorial "risk category" were all predictive of intraoperative blood loss. A history of previous gastrointestinal bleeding or an operation that involved the right upper abdominal quadrant was not predictive of intraoperative blood loss. Although CMV infection is common after liver transplantation, the prophylactic use of CMV antibody-negative blood products in CMV-negative recipients receiving a liver from a CMV-negative donor in our series was not associated with postoperative CMV infection. The transplantation of a liver positive for anti-hepatitis B core antigen was associated with subsequent hepatitis B surface antigen seroconversion in two of four cases. Transplantation of an ABO-incompatible liver and the presence of rouleaux observed in pretransplant blood compatibility testing were both associated with a significantly higher mortality. A careful review of laboratory data and medical records of patients undergoing liver transplantation should enhance the ability to modify the approach to the allocation of limited blood resources and the care and management of these patients.