The programmed death (PD)-1 immune checkpoint inhibitor nivolumab (Opdivo(®)) is approved in the USA for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) who have progression on or after platinum-based chemotherapy and in the EU for the treatment of adults with locally advanced or metastatic NSCLC after prior chemotherapy. In previously-treated patients with advanced nonsquamous NSCLC, overall survival was significantly prolonged and the overall response rate was significantly higher in patients who received intravenous nivolumab 3 mg/kg every 2 weeks versus intravenous docetaxel in the pivotal CheckMate 057 trial. Progression-free survival did not significantly differ between patients receiving nivolumab and those receiving docetaxel. Intravenous nivolumab had a manageable adverse event profile (including immune-mediated adverse events) and was better tolerated than docetaxel in the CheckMate 057 trial. Thus, nivolumab is an important new option for use in previously-treated patients with advanced nonsquamous NSCLC.