Background Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and adverse cardiovascular outcomes, but mechanisms are unclear. We hypothesized that mild CKD independently predicts adverse outcomes in women with symptoms and signs of ischemia. Methods We categorized 876 women from the Women’s Ischemia Syndrome Evaluation cohort according to estimated glomerular filtration rate (eGFR) (eGFR ≥90 mL/min per 1.73 m2 normal, 60-89 mL/min per 1.73 m2 mild CKD, ≤59 mL/min per 1.73 m2 severe CKD). Time to death from all-cause and cardiovascular causes and major adverse outcomes were assessed by multivariate regression adjusted for baseline covariates. Results Obstructive coronary artery disease (CAD) was present only in few patients (39%). Even after adjusting for CAD severity, renal function remained a strong independent predictor of all-cause and cardiac mortality ( P < .001). Every 10-unit decrease in eGFR was associated with a 14% increased risk of all-cause mortality (adjusted hazard ratio AHR 1.14 1.08-1.20, P < .0001), 16% increased risk of cardiovascular mortality (AHR 1.16 1.09-1.23, P < .0001), and 9% increased risk of adverse cardiovascular events (AHR 1.09 1.03-1.15, P = .002). Conclusions Even mild CKD is a strong independent predictor of all-cause and cardiac mortality in women with symptoms/signs of ischemia, regardless of underlying obstructive CAD severity, underscoring the need to better understand the interactions between ischemic heart disease and CKD.