Mild renal insufficiency is increasingly recognized as an independent risk factor for cardiovascular disease. However, few data exist regarding its relation to risk of congestive heart failure (CHF), a major public health problem in the elderly. To determine if mild renal insufficiency is associated with risk of incident CHF in the elderly, we analyzed data from 3,618 participants in the prospective, community-based Established Populations for Epidemiologic Studies of the Elderly (EPESE), who had no known CHF and had serum creatinine levels measured from 1987 to 1989. Mean age of the study population was 78.3 +/- 5.4 years; 84% had creatinine values <1.5 mg/dl and 98% had creatinine values < or =2.0 mg/dl. Creatinine clearance (CrCl) was calculated using the Cockcroft-Gault equation. During 3.9 years of follow-up, 488 subjects developed incident CHF as defined by hospital discharge and death certificate data. In a multivariate proportional hazards model, CrCl was inversely associated with CHF risk (p value for trend <0.001). Those in the lowest quartile of CrCl (< or =36.9 ml/min) had a nearly twofold (hazards ratio [HR] 1.99, 95% confidence intervals [CI] 1.43 to 2.79) greater risk of incident CHF compared with those in the highest quartile (>57.4 ml/min). Renal insufficiency, defined as creatinine > or =1.5 mg/dl in men and > or =1.3 mg/dl in women, was also associated with increased CHF risk (multivariate HR 1.43, 95% CI 1.17 to 1.74). Thus, mild renal insufficiency was a strong independent predictor of CHF in this cohort, suggesting that serum creatinine may offer a readily accessible tool to identify elderly patients at risk for CHF.