Serum apoproteins A and B and LCAT activities were estimated in 80 patients, 46 with posthepatic cirrhosis and 34 with alcoholic cirrhosis. The cirrhosis patients were also divided into compensated, decompensated, and hepatic coma subgroups. Apo-A and LCAT activities were significantly decreased in both cirrhotic groups without any significant difference between posthepatitic and alcoholic cirrhotic groups, while Apo-B was decreased in hepatic coma patients only. The decompensated cirrhosis patients showed lower Apo-A levels than the compensated cirrhosis patients and hepatic coma patients showed still lower levels compared to decompensated subgroup, while no significant decrease was observed in LCAT activities between compensated and decompensated cirrhosis patients. Apo-A level was correlated more significantly with serum albumin level than the LCAT activity. The study confirms that Apo-A level is highly related to the degree of liver injury and also suggests that this decrease may be mainly due to impaired liver synthesis and that the serum levels of Apo-A and Apo-B can be utilized in the differential diagnosis of chronic liver diseases.