It is important to identify patients at risk for atherosclerotic renal artery stenosis because renal artery stenosis is a progressive disease and a potentially correctable problem. To determine the risk factors for atherosclerotic renal artery stenosis, we performed renal arteriography at the time of cardiac catheterization in 270 patients (M:F, 193:77, mean age: 59 years) with clinical ischemic heart disease. Before the procedure, demographic data, medical history, physical findings and laboratory data were obtained. The degree of coronary artery stenosis and renal artery stenosis was quantified with automatic edge detection technique. Significant renal artery stenosis, defined as a narrowing of the diameter by more than 50%, was identified in 28 (10%) patients. Three patients (1%) had bilateral disease. Significant coronary artery disease, defined as a narrowing of the diameter by more than 50%, was present in 231 patients (85%). By univariate logistic regression analysis, older age (68 ± 8 vs. 58 ± 10 years), the presence of hypertension (61% vs. 38%), the extent of coronary artery disease, a high fibrinogen level (391 ± 93 mg/dl vs. 335 ± 109 mg/dl), a low albumin level (3.9 ± 0.4 g/dl vs. 4.1 ± 0.4 g/dl), and a low hemoglobin level (12.5 ± 1.6 g/dl vs. 13.5 ± 1.6 g/dl) were associated with the presence of renal artery stenosis (p < 0.05). Serum lipids, lipoprotein(a), creatinine, sex, smoking, or diabetes were not associated. By multivariate logistic regression analysis, older age (OR: 2.43 analyzed by 10 years increment, p = 0.0001), the presence of hypertension (OR: 2.68, p = 0.039) and a higher fibrinogen level (OR: 1.63 analyzed by 100 mg/dl increment, p = 0.038) were significant risk factors of renal artery stenosis. Fibrinogen level was negatively correlated with albumin level (r = –0.18, p = 0.004). These results suggest that hyperfibrinogenemia as well as old age and hypertension are independent risk factors for atherosclerotic renal artery stenosis.