In recent years, by the usage of new immune therapeutic agents for cancer treatment, the neurologic adverse events began to be seen more frequently. Nivolumab, one of the immune checkpoint inhibitor, is a human IgG4 antibody that blocks programmed cell death protein 1 and is approved against metastatic melanoma, squamous cell lung cancer, renal cell carcinoma, and Hodgkin’s lymphoma after failure of prior line of chemotherapy. Here, we present a 40-year-old patient developing encephalopathy after treatment of Hodgkin’s lymphoma with the immune checkpoint inhibitor nivolumab. In literature, cases of autoimmune encephalitis after receiving combination therapy of immune checkpoint inhibitors ipilimumab and nivolumab were described before. As far as we know, this is the unique case of encephalopathy reported after monotherapy with nivolumab treatment used for Hodgkin’s lymphoma.