Chronic allograft nephropathy (CAN), cardiovascular mortality, and posttransplant malignancy are complications of conventional immunosuppression after kidney transplantation. The aim was to study feasibility of sirolimus (SRL) maintenance monotherapy in a pilot experience. All patients with SRL monotherapy of at least 6 months follow-up were included. In 19 patients, age 58 (34-74) years, SRL monotherapy was introduced 98.1 (49-193) months after transplantation by withdrawing concomitant immunosuppressants from protocols already including SRL or introducing SRL and withdrawing other immunosuppressants. Follow-up is 20.0 (6-41) months. One patient died from hepatocellular carcinoma, diagnosed before SRL monotherapy, with functioning graft. No rejections occurred. SRL trough concentration was 10.7 (4.6-16.1) microg/L. Creatinine (1.77 [1.0-2.9] mg/dL vs. 1.68 [0.8-3.3] mg/dL after 6 months, 1.97 [0.8-4.6] mg/dL at last follow-up; P=NS). Proteinuria increased tendentially (333 [67-893] vs. 890 [46-4011] mg/day). No significant changes of hemoglobin, triglycerides, or cholesterol occurred. SRL monotherapy late after kidney transplantation is feasible in selected patients.