All new renal transplant recipients with functioning allografts and serum creatinine less than 2.6 mg/dl within the first 3 month post transplant would be eligible for this study of the safety of enalapril 5 mg vs placebo. Patients with serum potassium persistently over 5.5 mEQ/L would be excluded. This is a double-blinded randomized control study. End-points of the study are a persistent rise in serum creatinine of >50% from baseline not otherwise explained by clinical evaluation, and persistent serum potassium >5.9mEQ/L. Study duration is 6 month. At the end of the study patients will be continued on ACEI if clinically stable