Immune checkpoint inhibitors are antibodies that reactivate cytotoxic T cells by blocking immunosuppressive molecules such as cytotoxic T-lymphocyte-associated antigen 4 (e.g. ipilimumab) and programmed cell death protein (e.g. nivolumab). They are increasingly used in the treatment of various cancers including melanoma, renal cell carcinoma, non-small-cell lung cancer, hepatocellular carcinoma, etc. [1]. Unbalancing the immune system leads to immune-related adverse events involving all of the tissues, including the liver. Herein we present a melanoma patient who developed moderate HBV-related acute hepatitis due to exaggerated immune response after ipilimumab and nivolumab use.