Immunoglobulin (Ig) serum levels have been assayed in 729 patients with liver cirrhosis of different etiologies, in order to evaluate their prognostic value. Serum levels of three classes of Ig resulted mainly elevated in the three etiological groups (post-hepatitic, post-alcoholic, cryptogenetic) and they were significantly related to the severity of the liver disease, evaluated according to the Child-Turcotte score. The computerized analysis of the survival curves of patients with IgG, IgM, IgA values normal or elevated demonstrated an adverse prognostic rate in those with elevated Ig values. The difference among the survival curves, compared by the Lee-Desu method, was statistically significant (p less than 0.001). Our data suggest that the Ig levels can be considered as a prognostic index in liver cirrhosis patients.