This article focuses on the main patterns of damage that are seen in liver allograft biopsies. As with the interpretation of liver biopsies from the native liver, clinicopathological correlation is very important. The therapeutic implications of the biopsy report should also be considered, in particular whether changes in immunosuppression are indicated. For some conditions, such as liver allograft rejection, histology remains the gold standard for diagnosis. In other cases, a likely cause of graft dysfunction may already have been identified by other methods, but liver biopsy still provides useful additional information (e.g., assessing disease severity in hepatitis C infection) and may identify an additional or alternative cause for graft dysfunction (e.g., coexistent metabolic fatty liver disease). In cases where there is a dual pathology, liver biopsy may also help to identify the predominant cause of graft damage.