Background: over the past few years, multiple clinical trials have shown that immune checkpoint inhibitors (ICI) are active in NSCLC treatment. In 2015, survival improvement was demonstrated with second line immunotherapy. More recently, benefit was proven in the first line setting, both with ICI alone or in combination with chemotherapy. How fast the medical community has incorporated these advances into its clinical practice needs to be evaluated, as well as ICI efficacy in a real-world setting. Methods: retrospective analysis of the Oncoclinicas Data Lake was carried out to extract and curate information on the use of ICI in NSCLC patients from 2015 onwards, as well as survival outcomes from start of treatment to death or last follow-up. Patients with actionable driver alterations were excluded from this analysis. Results: 767 patients were identified. Median age was 72 years, 54% were male. The number of patients treated with ICI increased dramatically in the period, from 13 in 2015 to 243 in 2020. Most patients (86%) received ICI in the second line or beyond in 2015, while in 2019 and 2020 the preference was immunotherapy in the first-line setting (60%). The transition from platinum-refractory to the first line was observed for both ICI single agents and ICI combinations. As of 2021, 75% of ICI + chemotherapy treatments take place in the first line setting and 54% of ICI monotherapy treatments are given in first line setting. Overall, median overall survival was 15.7 months for first line setting use of ICI (CI 95% 12.2-19.6) and 11.6 months for second line and beyond (CI 95% 8.9-14.2). Survival rates at 12 and 24 months for first line ICI use were 56% and 48.5% and for second line and beyond 35% and 25.5%, respectively. Conclusions: ICI was promptly incorporated into the treatment of NSCLC and its use has shifted from platinum-refractory to treatment-naïve setting, mostly with combination regimens. Our cohort shows real-world overall survival rates comparable with published literature, despite a more elderly population than clinical trials.