Objective: Contrast media induced nephropathy (CIN) is diagnosed as the acute renal failure developed following intravenous contrast media usage when all other causes of renal failure are excluded. In this study, we investigated the effects of captopril given before coronary angiography (CA) on CIN development. Methods: A total of 80 patients, 43 males and 37 females, mean age: 58 ± 8 years (range: 18-80), with serum creatinine level below 2 mg/dl, who underwent coronary angiography in Cardiology Clinic of Izmir Atatürk Training and Research Hospital between October 2000- February 2002, were included into the study. Captopril was administered in 48 patients 8 hours and an hour before CA (Captopril group). Remaining 32 patients had no captopril treatment (Control group). There were no significant differences between the groups by means of clinical and biochemical parameters. The levels of serum creatinine and serum urea and creatinine clearance in 24 hours urine were measured before CA application and 48 hours after the procedure. Results: Five patients (8.3%) in the Captopril group and 1 patient (3%) in Control group developed CIN and this difference was statistically significant (p=0.02). Conclusion: Captopril is a risk factor for development of contrast media induced nephropathy.