Basal energy expenditure was measured by indirect calorimetry in 12 cirrhotic patients with hepatocellular carcinoma. Values were compared to those observed in 12 cirrhotic patients without hepatocellular carcinoma but with similar nutrition status. Energy expenditure was also predicted in each patient by the Harris-Benedict equation. Basal energy expenditure, whether expressed as kilocalorie per day or corrected for kilogram body weight or for kilogram fat-free mass, was found increased in cirrhotic patients with hepatocellular carcinoma. These patients expended an average of 250 kcal/day more than was expected given their body size. The highest values were observed in the patients who experienced a recent significant weight loss. Our study demonstrates that the presence of hepatocellular carcinoma on liver cirrhosis increases the metabolic rate of patients. This factor could contribute to progressive malnutrition in patients with hepatocellular carcinoma and should be taken into consideration when these patients are given nutritional support.