The clinical, biochemical, histopathological and immunological features of 30 cases of clometacin-induced hepatitis are described. The age range of the patients was 32-84 years with a notable female predominance of 29:1. The hepatitis was highly cytolytic with high values of transaminases but with little or no cholestasis. Gammaglobulins were higher than 18 g/l in 73% of the cases. 25 liver biopsies were performed and showed acute hepatitis with a predominant centrilobular necrosis in 17; chronic aggressive hepatitis was noted in 8 cases but 1 showed concomitant cirrhotic changes. Anti-tissue antibodies were looked for in all cases. Anti-smooth muscle antibodies of anti-actin cable type (titre 1/80 to 1/2, 560) were detected in 19 cases, anti-nucleus antibodies in 16 cases which were associated to the former in 14 cases. The above findings show that clometacin produces a hepatitis syndrome quite akin to autoimmune chronic active hepatitis (lupoid hepatitis) and to the hepatopathy induced by oxyphenisatin.