Nowadays we have novel equipment for lung cancer diagnosis, however; due to lack of symptoms, lung cancer is still diagnosed at a late stage. Currently we have the following therapies for non-small cell lung cancer: a) non-specific cytotoxic agents, b) targeted therapies and c) immunotherapy. Each therapy has its own advantages and adverse effects. In the current case we will present a rare case of psoriacic arthritis that was presented after two cycles of nivolumab administration and we will also present a review of the literature.