Checkpoint inhibitors targeting CTLA4 (Cytotoxic T-lymphocyte antigen-4), PD-1 (programmed death)1 on lymphocytes and PD-L1 (programmed death ligand)1 on tumors cells are novel and promising treatment options for different types of cancer. But these agents are double edged swords, they undoubtedly robust the anti-tumor response but also throttle up the normal immunologic homeostasis. Autoimmune adverse reactions are very common with checkpoint inhibitors. We present a case of bullous pemphigoid, as an adverse reactions to Avelumab treated urinary bladder cancer with liver metastasis.