The authors report a rare case of fulminant adenoviral hepatic necrosis occurring after chemotherapy in a patient with a second relapse of acute myeloid leukemia. The literature is reviewed and the role of rapid viral diagnosis in the clinical management of this complication is discussed. A 10-year-old girl with relapsed acute myeloid leukemia after allogeneic bone marrow transplant underwent re-induction chemotherapy with high-dose cytosine arabinoside and amsacrine. During induction she developed diarrhea and a marked coagulopathy, followed by fulminant hepatic failure and acute pre-renal failure. She rapidly deteriorated and died. A limited autopsy was performed. Adenovirus type 5 was cultured from ante mortem clinical samples and detected by polymerase chain reaction in postmortem samples of heart blood, lung, trachea, spleen, and liver. At autopsy, the liver demonstrated massive hepatic necrosis with positive immunofluorescence for adenovirus. Electron microscopy demonstrated intranuclear inclusions, typical of adenovirus. There was no evidence of pneumonia. Adenovirus can cause fulminant hepatic necrosis following chemotherapy in a nontransplant setting. If adenoviral disease is suspected, appropriate rapid viral studies should be undertaken, because early intervention with ribavirin or cidofovir may prevent rapid fulminant progression. Further studies on the role of antiviral therapy in this setting are warranted.