The purpose of this study was to evaluate protein-losing enteropathy in cirrhotic patients by assaying the intestinal clearance of alpha 1 antitrypsin (C alpha 1), 28 patients were divided into 5 groups: group A = 4 controls, group B = 6 patients with peptic ulcer, group C = 5 cirrhotic patients without esophageal varices (EV), group D = 6 cirrhotic patients with EV but without ascites, group E = 7 cirrhotic patients with EV and ascites. A significant increase in C alpha 1 was found only in groups D and E. The C 1 level was equal to the mean level found in controls multiplied by 2.5 and added to 2 standard deviations. Increases in C alpha 1 levels were not statistically significant when ascites or gastrointestinal involvement were present. C alpha 1 was significantly correlated to the size of EV (p greater than 0.05) and with the Child ratio (p greater than 0.01). No significant correlation was found between C alpha 1 and serum albumin or prothrombin.