Over a period of 16 years (1971-87) all cases of chronic active hepatitis (CAH) diagnosed following liver biopsy have been reviewed to assess incidence, aetiology, outcome and response to treatment. North Tees District serves a population of 210,000 and 26 cases were identified (20 female) age range 9-73 years (median 56 years). Incidence remained constant at 1:100,000/year. Twenty cases (77%) had an immune aetiology. Other aetiologies were hepatitis B virus (HBV) infection, alpha-1AT deficiency, non-A non-B hepatitis and a complex multisystem disease. The median follow-up period was 50 months. There were 7 deaths, three unrelated to liver disease. Survival analysis gives an 86% 5-year survival and 56% 10-year survival. Twenty four patients were treated with steroids (and 6 additionally with azathioprine); 15 (63%) were steroid responsive and 9 were non-responsive. In five patients steroids were successfully discontinued but in 10 patients severe symptomatic relapse occurred on steroid reduction below 7.5-10 mg/day. Steroid non-responders were not typical CAH, 5 with predominantly a rise in alkaline phosphatase, one multisystem disease and one HBV positive. Steroid discontinuation was only possible in one third of the patients responding. Eighteen subjects (69%) were cirrhotic at initial biopsy; 9 had follow-up biopsies, 6 were unchanged but three had progressed to cirrhosis despite apparent steroid responsiveness.