OKT3 has emerged as a highly effective antirejection therapy, but its efficacy in pancreas transplantation remains to be determined. During a 26-mo period, 46 vascularized pancreas transplants were performed with pancreaticoduodenocystostomy. Twenty-one patients (45.7%) were treated with OKT3. Indications for OKT3 use included steroid- and/or antilymphoblast globulin-resistant rejection in isolated-pancreas transplant (n = 8) or simultaneous pancreas-kidney-transplant (n = 13) recipients. A total of 46 rejection episodes occurred (mean 2.2). OKT3 was administered for a 14-day course concomitant with pulsed corticosteroids, azathioprine, and cyclosporin. OKT3 rescue therapy was successful in 13 cases (61.9%). The mean time to rejection reversal was 8.8 days (range 5-14 days). In isolated-pancreas transplants, OKT3 reversed only 1 episode of rejection (12.5%). In contrast, 12 episodes (92.3%) of allograft rejection were responsive to OKT3 in simultaneous pancreas-kidney recipients (P less than .05). Graft loss from rejection occurred at a mean 5.5 mo posttransplantation. OKT3 therapy was more successful in the setting of early rejection, rejection in combined pancreas-kidney transplants, and rejection not associated with hyperglycemia. No graft loss due to infection or patient death has occurred after OKT3 therapy. After a mean follow-up of 17.3 mo, patient survival was 89.1%, and allograft survival was 26.3% in isolated-pancreas and 85.2% in simultaneous pancreas-kidney transplants (P less than .05). Salvage therapy with OKT3 is a safe and effective means of reversing rejection in pancreas-allograft recipients. OKT3 is more effective in simultaneous pancreas-kidney recipients due to the earlier diagnosis of rejection.