Although branched chain amino acid (BCAA) supplementation improves malnutrition in cirrhotic patients, patient compliance with the administration of BCAA-rich supplements is poor due to their bitter taste. Since temperature is an important factor affecting taste, we examined the effect of heating on the stability of BCAAs and on the compliance of patients with liver cirrhosis with BCAA-rich supplement administration. A thermal denaturation test was first conducted, in which the BCAA-rich supplement Aminoleban® EN was heated to 37, 60, or 80°C for 30 or 60 min. The concentration of three amino acids, L-valine, L-leucine and L-isoleucine, was subsequently measured. The nutritional status of the cirrhotic patients was also evaluted. Patients presenting liver failure with a Child-Pugh class of A (n=2), B (n=2) or C (n=2) were hospitalized at Kurume University Hospital. Six patients with liver cirrhosis (HCV, n=3; HBV, n=1; alcohol, n=2) were enrolled. Venous blood samples were drawn in the morning after a 12-h overnight fast. The BCAA-rich supplement was administered to patients at room temperature (25°C) or heat loaded at 60°C for 10 min, with the temperature maintained above 45°C. Each patient was interviewed by a nationally registered dietitian regarding food consumption and intake of the BCAA-rich supplement immediately after each meal. Nutritional status was evaluated according to serum albumin levels, blood hemoglobin, prothrombin time and total lymphocyte count. No significant decrease was noted in valine, leucine or isoleucine levels following the heating of the BCAAs to 80°C. The caloric intake of the BCAA-rich supplement was significantly higher with administration after heating to 60°C, compared to caloric intake with administration at 25°C. In addition, heating of the BCAA-rich supplement significantly increased blood lymphocyte counts. In conclusion, heating did not affect the stability of the BCAAs, and may improve compliance with BCAA-rich supplement administration. As a result, the nutritional status of cirrhotic patients may be improved.