Chronic renal insufficiency (CRI) is a predictor of stroke, cardiovascular, and all-cause mortality, but the mechanisms responsible for these associations are unclear. Whether CRI was associated with severity of coronary artery disease (CAD) as measured by exercise stress echocardiography among outpatients with stable CAD was evaluated. This study is a cross-sectional analysis of the Heart and Soul study, a prospective cohort of patients with known CAD. Renal function was assessed by 24-h urine collection, and CRI was defined as measured creatinine clearance < or =60 ml/min. Exercise stress echocardiography was used to identify inducible ischemia, defined as any wall motion abnormality seen at stress but not at rest. Logistic regression was used to evaluate the association of CRI with exercise-induced ischemia after adjustment for cardiovascular risk factors. Participants with CRI composed 97 (23%) of the 431 participants and were characterized by older age, worse CAD, lower ejection fraction, greater left ventricular mass and higher C-reactive protein values. The prevalence of exercise-induced ischemia was also substantially greater in the participants with CRI (42% versus 23%; odds ratio [OR], 2.3; 95% confidence interval [CI], 1.4 to 3.8; P < 0.001). This association was minimally changed by adjustment for traditional cardiovascular risk factors and coronary disease history (OR, 2.0; 95% CI, 1.3 to 3.3; P < 0.01) and remained strong even after adjustment for C-reactive protein (OR, 2.3; 95% CI, 1.0 to 5.1; P = 0.04). CRI is strongly associated with exercise-induced ischemia in patients with CAD. The greater severity of atherosclerotic disease observed in patients with CRI may in part explain the association of CRI with increased cardiovascular risk among individuals with CAD.