The aim of this study was to evaluate the effect of administration of angiotensin II type I receptors blockers on patients’ variables in renal transplantation. Fifty transplant patients were randomized into two groups: treated with losartan (group A: n=25) and without (group B: n=25). Group A received losartan for one year. Blood pressure, serum creatinine, potassium, haemoglobin, low density lipoprotein- cholesterol (LDL-C), high density lipoprotein- cholesterol (HDL-C), triglyceride (TG), uric acid, and creatinine clearance and serum cyclosporine level were measured at baseline and after one year follow up. The patients consisted of 30 males and 20 females with a mean age of 40±13 years. Between the groups, there were no differences in baseline variables such as blood pressure, serum creatinine, potassium, haemoglobin, uric acid, cyclosporine level, lipid profile, creatinine clearance and dosing of cellcept, ferrous sulfate, folic acid and statins and other antihypertensive drugs. After one year follow up, losartan group had lower systolic blood pressure compared with control (113 ± 22 vs 126 ± 18 mmHg, p=0.036). Serum HDL-C was higher in losartan group than control (58 ± 22 vs 47 ± 10 mg/dL, p=0.03). Losartan group had lower haemoglobin compared with control (12.8 ± 1.9 vs 14.5 ± 2.1 g/dL, p= 0.006). 25% patients in losartan group had haemoglobin lower than 12 g/dL compared with 4% in control group (p= 0.097). After one year, there were no significant differences in serum creatinine, creatinine clearance, serum potassium, LDL-C, TG, and uric acid. This study suggests that losartan has effects on increasing serum HDL, lowering haemoglobin and systolic hypertension, but no effect on uric acid and renal function in kidney transplant patients.