A 25-year-old man presented with fulminant hepatic failure from an unusual peripheral T cell lymphoma involving the liver and spleen without lymphadenopathy. He underwent liver transplantation before establishing a definitive diagnosis and 21 days later, died from liver allograft failure because of recurrent lymphoma. In both the native liver and hepatic allograft, the lymphoma presented as a sparse cytologically atypical malignant infiltrate intermixed with numerous reactive macrophages, which showed marked angio- and epitheliotropism and irregular areas of coagulative necrosis. The malignant cells were CD3+/ granzyme B+/TIA1+/CD8-/CD56-/S100-- with variable staining for beta F1, CD5, and CD7. Multiplex polymerase chain reaction (PCR) showed rearrangement of the T cell receptor gamma chain gene in the native and transplanted liver and spleen. Even in the absence of a mass lesion or lymphadenopathy, peripheral T cell lymphoma should be included in the differential diagnosis of fulminant hepatic failure in young patients who show no evidence of viral or autoimmune diseases.