Acute liver failure(ALF) is an uncommon disease in the United States,affecting more than 2 000 people each year.Of all the various causes,malignant infiltration is one of the least well known and carries with it a high mortality.We describe a case of ALF as the presenting manifestation of peripheral T-cell lymphoma in an elderly woman.By reporting this case,we hope to increase early recognition of this disease process in order to potentially improve treatment outcomes.