The blockade of the renin-angiotensin-aldosterone system may limit the progression of graft dysfunction in patients receiving kidney transplantations. We retrospectively evaluated the safety and efficacy of angiotensin-converting enzyme inhibitors (ACEI) in renal allograft recipients. Fifty-seven cadaveric kidney recipients (58% of recipients), were prescribed an ACEI (lisinopril). The indications for ACEI were isolated proteinuria (1 patient), erythrocytosis (6 patients), and arterial hypertension (50 patients). The choice of an ACEI for blood pressure control was due to presence of left ventricular hypertrophy (2 patients), mild proteinuria (4 patients), and high hemoglobin (4 patients). There was a significant reduction in the mean arterial pressure after 1 month (P = .0004) and 1 year (P = .0002) of therapy. Overall, the estimated glomerular filtrate rate (eGFR), calculated using the Cockcroft-Gault equation, remained unchanged. Among patients who had serum creatinine values above 2.0 mg/dL at the beginning of ACEI therapy, there was a significant rise in eGFR from 39.3 +/- 13.2 to 44.1 +/- 16.8 mL/min after 6 months (P = .01), and 43.3 +/- 17.3 mL/min after 1 year (P = .04). In patients with erythrocytosis, the hemoglobin showed a significant and sustained reduction after 1 month (P = .004) and 1 year (P = .001). Six patients suspended ACEI owing to adverse events: cough (n = 4), worsening of graft function (n = 1), and hypotension (n = 1). Six patients required erythropoiesis-stimulating agents. No patient suspended treatment owing to hyperkalemia. In conclusion, ACEI were well tolerated, safe, and effective antihypertensive agents in kidney graft recipients. They seemed to have some beneficial effect in preserving GFR in patients with worse graft function.