The occurrence and distribution of fibronectin (FN) was assessed by an immunoperoxidase technique in liver biopsies from alcoholics without and with acinar zone 3 fibrosis of varying degrees. Increased amounts of FN was found diffusely in zone 3 areas with a perisinusoidal and pericellular localization. FN was closely correlating to the pattern of fibrosis but increased amounts of FN could also be seen in biopsies without fibrosis as visualized in Picro-Sirius stained sections. There was no topographical relationship to liver cells with fatty changes, Mallory bodies or to alcoholic hepatitis. It is made probable that FN is of significance in the development of early liver fibrosis in alcoholics and that FN may act as a chemotactic factor for collagen producing cells and as a skeleton for the new collagen formation.