We report the first case of auxiliary partial orthotopic liver transplantation (APOLT) in a patient with isoniazid (INH)-related fulminant hepatic failure (FHF) with the aim to determine the ability of the native liver (NL) to recover after this particular toxic event. A 10-year-old boy with INH-related FHF underwent APOLT after left hepatectomy on the NL. Neurological status and liver function rapidly improved, but, on postoperative day 22, urgent re-transplantation was needed for graft-hepatic artery thrombosis (HAT) and the NL's incapacity to sustain adequate liver function. Histological examination of the NL showed signs evident of its regeneration, however. In conclusion, though we faced the clinical failure of the NL functionally to sustain the patient in the presence of the graft HAT 3, weeks after APOLT, such a failure may be interpreted as time related. In fact, the histological picture in this particular case may suggest the potential for NL recovery after INH-related FHF.