Infiltration of the liver by secondary malignancies is a rare cause of acute liver failure. Acute liver failure caused by malignant infiltration is associated with almost 100% mortality and is typically diagnosed postmortem. Richter's transformation is a well-recognized complication of chronic lymphocytic leukemia. This transformation is the progression of chronic lymphocytic leukemia to a high-grade lymphoma. We describe the case of a 64-year-old man with a history of chronic lymphocytic leukemia who presented with acute liver failure. Liver biopsy revealed hepatic infiltration by a high-grade lymphoma. The patient responded to chemotherapy with normalization of hepatic function and remained disease-free after eight months. This case represents the first report of Richter's transformation presenting as acute liver failure. It also represents the fourth reported case of a patient with acute liver failure secondary to involvement by a hematopoietic malignancy that was successfully recognized and treated.