BACKGROUND: Altered renal vasodilatation and oxidative stress are important mechanisms of contrast-induced nephropathy (CIN). The aim of the present study was to assess the effect of nebivolol, a beta blocker, on prevention of CIN. We hypothesized that nebivolol may prevent CIN due to its renal vasodilatation and antioxidant effects. METHODS: Thirty-two Wistar-albino rats were divided into four groups (n = 8 each): control (C), contrast media (CM), nebivolol (N), and nebivolol + contrast media (NCM). CIN was induced by administration of intravenous high-osmolar contrast media diatrizoate (6 ml/kg) after 72 h of dehydration. Nebivolol (2 mg/kg) was given internally once daily for 5 days. Kidney function parameters, nitric oxide metabolites and oxidative stress markers were measured. Kidneys were excised for pathological evaluation. RESULTS: The decrease of creatinine clearance was 0.180 +/- 0.11 mg/dl in CM, and 0.030 +/- 0.10 mg/dl in NCM (P = 0.01). Microproteinuria was ameliorated using nebivolol (P = 0.001). Serum protein carbonyl content, malonyldialdehyde and kidney thiobarbituric acid-reacting substances levels were higher in CM than in C (P = 0.003, P < 0.001 and P = 0.034, respectively) and serum thiol was lower in CM than in C (P = 0.001). However, oxidative stress markers were similar in NCM and C. Diatrizoate decreased kidney nitrite levels, but nebivolol increased them (P = 0.027). Nebivolol attenuated the tubular necrosis, proteinaceous casts and medullary congestion, although significant protective effects, were observed in tubular necrosis (P = 0.001) and proteinaceous cast (P < 0.001). CONCLUSION: This study demonstrated the protective role of nebivolol against CIN.