Murine monoclonal CD-3 antibody (OKT3) is a significant new addition to the immunosuppressant armamentarium for treatment of heart transplant rejection. In the Utah Transplantation Affiliated Hospitals (UTAH) Cardiac Transplant Program, Salt Lake City, a broad experience with OKT3 has been acquired. Fifteen patients were treated for refractory rejection, whereas 68 patients were treated for early rejection prophylaxis therapy utilizing either 10- or 14-day protocols. To facilitate early hospital discharge, 12 patients were able to complete OKT3 therapy as outpatients. A retrospective review of length of initial hospital stay and clinical results revealed that patients who received OKT3 had an average hospital stay (+ standard deviation) of 17.1 days, and their 12-month survival was 96%. Patients who received antithymocyte globulin and/or steroids had an average stay of 27.4 days (p less than 0.05) and a 12-month survival of 93%. In conclusion, the possibility for reduced hospital stay and consequent cost reduction exists with the use of OKT3, especially when completion of therapy can be managed in an outpatient setting.