Background.Auxiliary partial orthotopic liver transplantation (APOLT) has recently been performed in patients with noncirrhotic metabolic liver diseases. However, long-term outcomes for the preserved native liver and the transplanted liver graft have not been clearly established yet.Methods.The recipient was a 36-month-old girl with ornithine transcarbamylase deficiency. She underwent APOLT, using her father's left lateral segment.Results.Liver function was normalized soon after APOLT and the patient was able to ingest a normal diet without medication. Coexistence of the well-functioning native liver and graft was demonstrated in a computed tomography scan, Doppler ultrasonography, scintigraphy, and histological examination, during a relatively long-term follow-up period.Conclusions.APOLT seems to be most useful for the treatment of noncirrhotic metabolic liver diseases.