A cohort of 432 ESRD (261 hemodialysis and 171 peritoneal dialysis) patients was followed up prospectively for an average of 41 months. Baseline and annual demographic, clinical, and echocardiographic assessments were performed, as well as serial clinical and laboratory tests measured monthly while patients were on dialysis therapy. Among hemodialysis patients, after adjustment was made for age, diabetes, and ischemic heart disease, as well as hemoglobin and blood pressure levels measured serially, a 10-g/L fall in mean serum albumin level was independently associated with the the development of de novo (relative risk [RR], 2.22; P = 0.001) and recurrent cardiac failure (RR, 3.84; P = 0.003), de novo (RR, 5.29; P = 0.001) and recurrent ischemic heart disease (RR, 4.24; P = 0.005), cardiac mortality (RR, 5.60; P = 0.001), and overall mortality (RR, 4.33; P < 0.001). Among peritoneal dialysis patients, a 10-g/L fall in mean serum albumin level was independently associated with the progression of left ventricular dilation as seen on follow-up echocardiography (beta, 13.4 mL/m2; P = 0.014), the development of de novo cardiac failure (RR, 4.16; P = 0.003), and overall mortality (RR, 2.06; P < 0.001). Hypoalbuminemia, a major adverse prognostic factor in dialysis patients, is strongly associated with cardiac disease.