The aim was to evaluate long-term graft survival and function after conversion to sirolimus (SRL) for chronic calcineurin inhibitor (CNI) toxicity and the predictive value of baseline proteinuria. This is a follow-up conversion study of 59 renal transplant patients with deteriorating graft function and histologic signs of CNI toxicity. Previously, baseline proteinuria <800 mg/day was identified as a short-term predictor for successful conversion. Follow-up was 5.3 +/- 0.8 (3.7-6.8) years. Patient survival was 88%, graft survival 38%. Creatinine clearance at the last follow-up was 33.7 +/- 14 ml/min, proteinuria 826 +/- 860mg/day. Baseline proteinuria <800 mg/day was associated with better graft survival. In a cox analysis including proteinuria >800 mg, glomerular filtration rate, age at conversion, chronic Banff score at conversion and time after transplantation at conversion, higher proteinuria was associated with a relative risk of graft loss of 3.98. Prognosis of chronic allograft dysfunction is poor. However, conversion to SRL remains an option for patients with low baseline proteinuria, which can slow down deterioration of graft function during a follow-up period of up to 5 years.