Non-A, non-B or seronegative hepatitis is the leading indication for liver transplantation in patients with fulminant hepatic failure (FHF). We examined protocol annual review liver allograft biopsy specimens in consecutive adult patients transplanted for FHF in an attempt to determine the extent of the histological changes. One hundred eleven biopsy specimens from 41 patients transplanted for fulminant seronegative hepatitis and 34 from a comparison group of 16 patients transplanted for other causes of FHF (11 paracetamol overdose, 2 idiosyncratic drug reaction, 3 Wilson's disease) were available. Specimens were analyzed using standard proforma without knowledge of the original diagnosis. Chronic hepatitis was present in 29 patients (71%) transplanted for fulminant seronegative hepatitis (23 mild, 3 moderate, and 3 severe) compared with 5 patients (31%, all mild) transplanted for other causes of FHF. Twenty-five patients (61%) grafted for seronegative FHF had fibrosis (13 mild, 9 moderate, and 3 severe) in contrast to 4 fibrosis (25%) (all mild) in the comparison group. Excluding early allograft failure because of primary graft nonfunction or vascular complications, six patients with seronegative FHF required retransplantation (2 = chronic rejection; 1 = severe hepatitis with panacinar necrosis, resembling original liver; and 3 = chronic hepatitis with precirrhotic fibrosis and prominent cholestasis of unknown cause). One patient in the comparison group had a second graft (chronic rejection). Posttransplantation chronic hepatitis is more frequent and severe in patients transplanted for seronegative hepatitis. Graft survival may be adversely influenced by the development of chronic hepatitis, which may represent persistent or recurrent disease.