BACKGROUND: Nivolumab has shown a survival benefit compared with docetaxel as second-line treatment for patients with previously treated advanced squamous non-small cell lung cancer (NSCLC) in a randomized phase III trial. The experiences of patients and physicians in routine clinical practice are often different from those in a controlled clinical trial setting. We present data from the entire Italian cohort of patients with squamous NSCLC enrolled in a worldwide nivolumab NSCLC expanded access program. PATIENTS AND METHODS: Patients with pretreated advanced squamous NSCLC received nivolumab 3 mg/kg every 2 weeks for up to 24 months. Safety was monitored throughout; efficacy data collected included objective tumor response, date of progression, and survival information. RESULTS: The Italian cohort comprised 371 patients who received at least one dose of nivolumab. In the overall population, the objective response rate (ORR) was 18%, the disease control rate (DCR) was 47%, and median overall survival (OS) was 7.9 months (95% confidence interval 6.2-9.6). In subgroup analyses, ORR, DCR, and median OS were, respectively, 17%, 48%, and 9.1 months in patients previously treated with two or more lines of therapy (n = 209) and 8%, 40%, and 10.0 months in patients treated beyond disease progression (n = 65). In the overall population, the rate of any-grade and grade 3-4 adverse events was 29% and 6%, respectively. Treatment-related adverse events led to treatment discontinuation in 14 patients (5%). There were no treatment-related deaths. CONCLUSION: To date, this report represents the most extensive clinical experience with nivolumab in advanced squamous NSCLC in current practice outside the controlled clinical trial setting. These data suggest that the efficacy and safety profiles of nivolumab in a broad, real-world setting are consistent with those obtained in clinical trials. IMPLICATIONS FOR PRACTICE: Nivolumab is approved in the U.S. and Europe for the treatment of advanced non-small cell lung cancer (NSCLC) after failure of prior platinum-based chemotherapy. In this cohort of Italian patients with previously treated, advanced squamous NSCLC treated in a real-world setting as part of the nivolumab expanded access program, the efficacy and safety of nivolumab was consistent with that previously reported in nivolumab clinical trials.