Aprotinin, a bovine protease inhibitor, has been used extensively in patients undergoing cardiac surgical procedures in an effort to minimize blood loss and prevent the complications associated with blood replacement. We sought to evaluate the effect of aprotinin on postoperative blood loss, renal function, and the incidence of right ventricular failure in patients undergoing placement of a TCI Heartmate left ventricular assist device as a bridge to cardiac transplantation. Retrospective data analysis in 142 patients (42 receiving aprotinin and 100 untreated) demonstrated that the use of aprotinin was associated with a significant decrease in postoperative blood loss (p = 0.019) and in the intraoperative packed red blood cell transfusion (p = 0.019) and total blood product (p = 0.016) requirements. A transient, yet significant, increase in the postoperative creatinine level in the aprotinin group (p = 0.0006), but not in blood urea nitrogen level (p = 0.22), was noted. Interestingly, we noted an association between blood loss and the subsequent development of right ventricular failure; patients who required a right ventricular assist device bled significantly more than did those who did not suffer right ventricular failure (p = 0.02). Additionally, aprotinin recipients benefited by a reduction of nearly one half in the incidence of the need for a right ventricular assist device. The incidence of perioperative mortality was reduced in those receiving aprotinin compared with that in untreated patients, (p = 0.05). We conclude that aprotinin is safe and effective in decreasing postoperative blood loss and intraoperative blood product requirements, and in reducing perioperative mortality in patients undergoing left ventricular assist device placement as a bridge to cardiac transplantation.