Renal artery stenosis (RAS) is a major comorbid condition in patients with coronary artery disease (CAD). Although the reported prevalence of significant RAS among patients undergoing coronary angiography varies from 6.2 to 28% in Western countries, little information is available on the prevalence and predictors of RAS in Middle Eastern countries. From April 2007 to May 2008, 732 hypertensive patients with suspected CAD immediately after selective coronary angiography underwent abdominal aortography with or without selective renal angiography. Coronary angiography revealed stenosis of > or =50% in at least one of the main coronary vessels in 434 (59.3%) patients, including 100 (13.7%) cases with single-vessel CAD, 114 (15.6%) with two-vessel CAD and 220 (30.1%) with three-vessel CAD. Significant RAS was present in 87 patients (11.9%), severe (> or =75%) RAS in 35 patients (4.8%) and bilateral RAS in 37 patients (5.1%). Higher serum creatinine level, severity of CAD, history of coronary artery bypass graft surgery (CABG), congestive heart failure, and pulmonary edema together with atrial fibrillation were the most powerful predictors of significant RAS. In multivariate logistic regression analysis, three-vessel CAD (odds ratio 1.61, 95% confidence interval (1.36-1.91), P<0.001), history of CABG (odds ratio 4.40, 95% confidence interval (1.17-16.5), P=0.028) and serum creatinine level of >1.2 mg per 100 ml (odds ratio 2.12, 95% confidence interval (1.09-4.12), P=0.026) were the most powerful predictors of significant RAS. The prevalence of RAS in our patients was similar to that reported in the Western countries. The presence of multi-vessel CAD or a history of CABG along with a higher serum creatinine level in hypertensive patients undergoing coronary angiography was found to be a risk factor for RAS.