Four cardiac transplant candidates were supported with ventricular assist devices for periods ranging from 53 to 90 days (mean, 75 days). The patients were men who ranged in age from 36 to 49 years (mean, 44.5 years). Two patients had Pierce-Donachy biventricular assist devices (BVADs) and two patients had Novacor left ventricular assist systems (LVASs). Complications included infection (3 patients), development of antibodies (2 patients), bleeding (2 patients), and pump inflow obstruction (1 patient). All patients were maintained on an anticoagulation regimen which included warfarin and dipyridamole. They were extubated and ambulatory for most of the period of mechanical support. Thromboembolic complications did not develop in any of these patients, and they did not acquire infections which involved the mediastinum. They were successfully transplanted and discharged 11 to 25 days after transplantation. Although major complications were common in this small group of patients, all four patients achieved hemodynamic stability and became excellent candidates for cardiac transplantation. With proper patient selection and meticulous nursing care, current mechanical circulatory support technology is capable of maintaining patients consistently for periods of greater than 50 days.