Background/Aims: Chronic allograft nephropathy is the main cause of late graft loss and nonimmunological factors, including hypertension and proteinuria, the principal etiological factors. In this context, blockage of the renin-angiotensin system could be helpful. The aim of the present study was to review the renoprotective efficacy of losartan in a large group of renal transplant patients undergoing long-term follow-up. Methods: A retrospective analysis of 276 renal transplant patients treated with losartan was performed. The indication for losartan was arterial hypertension in 163 patients, proteinuria in 37 patients and hypertension plus proteinuria in the remaining 76 patients. Clinical and biochemical parameters before starting losartan treatment (–6 months, –3 months and at baseline) and 3, 6, 9, 12, 18 and 24 months after the introduction of losartan were analyzed. Results: Arterial hypertension significantly decreased after the introduction of losartan (p = 0.000). Serum creatinine was significantly decreased by losartan therapy, and changes in the serum creatinine slope (1/sCr) before and after losartan were statistically significant. Proteinuria markedly decreased after the introduction of losartan. Clinical and biochemical tolerance of losartan was excellent in most patients and only 9 out of the 276 patients (3%) treated with losartan discontinued the drug because of an adverse event. During follow-up, only 3 patients required substitutive treatment with dialysis due to progressive deterioration of renal function in the context of chronic allograft nephropathy. Conclusion: Losartan demonstrated high efficacy as a renoprotective agent in renal transplant patients and could be useful in the treatment and prevention of chronic allograft nephropathy.