The metabolic effects of an acute acetate load have been investigated in chronic uremic patients and in controls. The decay rate of blood acetate levels was significantly lower in patients than in controls. Higher levels of blood acetoacetate and 2-oxoglutarate and plasma triglycerides were observed in the patients after the load. No difference was detectable in plasma levels of unesterified fatty acids and cholesterol between the two groups of subjects. Acetate oxidation in citric acid cycle may be reduced in uremia owing to a lack of coenzyme A. These observations raise the possibility that chronic acetate administration with the dialysate induces hypertriglyceridemia and accelerates the development of atherosclerosis in hemodialysis patients.