Pathologic evaluation of liver allograft biopsies is an essential component of management in patients following orthotopic liver transplantation. Liver allograft biopsy is considered “gold standard” for the diagnosis of T-cell mediated rejection. It is also used to confirm or exclude numerous allograft pathologies, including biliary issues, vascular insults, infection-related complications, and recurrent and de novo liver diseases. This chapter aims to cover all the aspects of liver allograft pathological findings.