Cardiovascular disease is a prevalent and serious complication after solid organ transplantation. Treatment with glucocorticoids is associated with increased risk for diabetes mellitus, insulin resistance, weight gain, hypercholesterolemia, and hypertension, all shown to be independent risk factors for cardiovascular disease. We sought to test the hypothesis that tapering of prednisolone (TAP) the first year after renal transplantation improves insulin sensitivity (IS), and to assess the effect of complete steroid withdrawal (SW) on IS in patients on a cyclosporine-based immunosuppressive regimen. All patients (n = 57) completed two consecutive hyperinsulinemic euglycemic glucose clamp procedures, a TAP group (n = 34) and a control group (n = 12) at 3 and 12 mo after transplantation, and a SW group (n = 11) before and 5 mo after SW. The IS index (ISI) was calculated as the glucose disposal rate divided by mean serum insulin the last 60 min of the clamp. In the TAP group, the mean (range) daily prednisolone was reduced from 16 (10 to 30) to 9 (5 to 12.5) mg accompanied by an average increased ISI of 24% (P = 0.008). In contrast, no significant change in ISI was observed in the control group (0%, P = 0.988). In the SW group, withdrawal of 5 mg prednisolone did not influence mean ISI significantly (-8%, P = 0.206). Lowering daily prednisolone toward 5 mg/d has beneficial effects on insulin action after renal transplantation, but withdrawal of 5 mg prednisolone may not influence IS significantly.