Twenty-nine patients of 18,000 inpatient admissions over a six-month period developed ischaemic hepatitis accompanied by peak aspartate aminotransferase (AST-EC 2.6.1.1) activity greater than 1,000 U/L. Seventeen of these 29 patients died either during or shortly after the episode of ischaemic hepatitis, with an overall mortality of 58.6%. Mortality was not due in any of the cases to the hepatitis but rather the underlying cause. Ischaemic hepatitis was the commonest cause of an AST activity greater than 1,000 U/L in this hospital population (29 of 52 patients i.e. 56%). This condition is more common than generally appreciated and is associated with a poor prognosis.