Abstract: AIM: To investigate incidental renal artery stenosis (RAS) in elderly patients under coronary artery angiography and to analyze the risk factors of RAS. METHODS: Renal artery angiography (RA) was performed in 277 patients following coronary angiography to screen for the presence of RAS in order to study the relationship between coronary artery disease (CAD) and RAS. RESULTS: The incidence of RAS was 19% (41/212) in patients with CAD who had been confirmed by coronary artery angiography. Five patients with RAS were found in 65 patients whose coronary arteries were normal (8%, 5/65). RAS incidence was higher in multivessel CAD than single-vessel disease (P<0.01). In multivariate analysis, the severity of CAD (OR=1.89, 95% CI: 1.35-2.65, P<0.01) was independently correlated with RAS. CONCLUSION: RAS incidence is higher in patients with CAD. RA should be performed routinely after patients have been identified with multivessel CAD by coronary artery angiography.