The impact of a prednisone-free immunosuppressive regimen was evaluated in simultaneous pancreas-kidney (SPK) recipients. Patient and graft survivals, rejection rates and the incidence of CMV disease were determined. Two hundred consecutive SPK transplant recipients received tacrolimus-based immunosuppression with (n = 100) or without (n = 100) chronic prednisone therapy. Patients were induced with lymphocyte depleting antibodies or IL-2 receptor blockers and received prophylactic antiviral therapy. Patient and graft survivals and rejection rates were not statistically significantly different between treatment groups. Two-year cumulative incidence of CMV in recipients in the prednisone-free protocol was reduced (7.2% vs. 16%; p = 0.15). Considering only recipients at highest risk (D+/R- or D+R+), incidence of CMV disease in the prednisone-free group (n = 61) compared to the steroid-treated group (n = 48) was reduced from 36% to 18% (p < 0.05). Multivariate analysis confirmed the independent effect of prednisone treatment on the incidence of CMV (RR 2.3; p = 0.04). In the prednisone-free protocol, incidence of CMV was less frequent in recipients receiving induction with Campath versus rabbit antilymphocyte globulin (2.4% vs. 12.6%; p = 0.14). Eliminating prednisone immunotherapy did not adversely affect outcomes and was associated with a reduced rate of CMV in SPK recipients of organs from sero-positive donors.