Objective: To determine the effects of supplementation with oral branched-chain amino acids (BCAAs) in serum albumin and cardiac function in heart failure patients with hypoalbuminemia. Methods: Forty heart failure patients with hypoalbuminemia were enrolled in our study. They were divided into experimental group (n=20) and control group (n=20). They all received recommended heart failure therapy, and BCAAs were administrated to experimental group. The during of the treatment is 30 days. Cardiothoracic ratio (CTR) were used for evaluate the cardiac function, the serum albumin was examined. Results: There was no significant difference in serum albumin and CTR between the two groups before treatment, P>0.05. Serum albumin in the experimental group after the treatment significantly increased than before and that in the control group [(3.45±0.42) g/dL vs (3.0±0.4) g/dL and (3.11±0.55) g/dL] and did not change in controls. CTR significantly decreased in the experimental group than before and that in the control group [(60.1±8.3)% vs (62.3±8.4)% and (62.2±8.2)%] and did not change in controls. Changes in the serum albumin level were positively correlated with changes in the cholinesterase level (r=0.76, P=0.03) and negatively correlated with changes in body weight (r=−0.74, P=0.04) and CTR (r=−0.61, P=0.01). Conclusion: Heart failure patients with hypoalbuminemia supplemented with BCAAs showed increased serum albumin and decreased CTR.