Fifteen patients with liver cirrhosis and 15 with primary liver cancer were studied. The results of cellular immunity in these two groups and a third control group of 15 healthy subjects were compared. A significant decrease in OKT3 and OKT4 lymphocytes and response to different mytogenic stimuli were found, particularly in the hepatocarcinoma group. No significant differences were observed in OKT8, OKM1 or chemotaxis.