: The systemic treatment of non-small cell lung cancer (NSCLC) has changed dramatically with the identification of actionable mutations and the use of targeted agents. Unfortunately, many tumors will acquire resistance and >75% of NSCLC cases lack for an actionable gene aberration. In this setting, immunotherapy rises as effective therapeutic where immune checkpoint inhibitors have entered or are entering the market in many neoplasms, including NSCLC. Ipilimumab is a monoclonal antibody targeting CTLA-4, promoting T-cell activation and its subsequent anti-tumoral immune effect. Ipilimumab might have a very important role in NSCLC as it does in melanoma because of its synergistic effect with PD-1/PDL-1 inhibitors. : We summarize current results of clinical studies of ipilimumab for efficacy and safety in NSCLC and also the current knowledge about potential biomarkers for its efficacy. : Combined use of PD-1/PDL-1 and anti-CTL4 inhibitors increases the efficacy against NSCLC and it is a very promising approach not only in NSCLC but also in small cell lung cancer (SCLC) for first or second-line therapy. It's very important to identify biomarkers that can better select the population of patients that benefit the most with these checkpoint inhibitors.