Hepatic innervation is thought to play an important role in the regulation of metabolism. Regenerating liver nodules in cirrhosis have a paucity of nerve fibers. The situation in chronic necroinflammatory and cholestatic liver diseases is unclear. We have therefore evaluated hepatic innervation in toxic hepatitis and non-specific reactive hepatitis. Liver biopsies from 42 patients considered to have chronic toxic liver injury, 25 patients with chronic reactive inflammatory infiltrates and variable degree of hepatic fibrosis and the control group comprising of 23 individuals who had undergone laparotomy for non-hepatic reasons (trauma etc.) and who had entirely normal hepatic histology were studied histologically and immunohistochemically for the presence of nerve fibres. Semiquantitative analysis showed significant proliferation of portal nerve fibers in biopsies confirmatory of toxic liver injury. Assessment of hepatic neural elements may be useful in the differential diagnosis of unspecified liver injury where toxic injury may be implicated.