Immune-checkpoint inhibitor (ICI) efficacy in patients with non-small cell lung cancer (NSCLC) harboring molecular alterations remains poorly elucidated. This study was undertaken to determine ICI efficacy against epidermal growth-factor receptor (EGFR)/anaplastic lymphoma kinase (ALK)/c-ros oncogene 1 (ROS1)-mutated NSCLC patients in the real-world setting. In this retrospective, multicenter study on adults with ICI-treated EGFR-mutated or ALK-or ROS1-translated NSCLCs, we analyzed clinical characteristics and outcomes: ICI-treatment duration, and progression-free survival (PFS), objective response rate, duration of response, and overall survival (OS) from immunotherapy initiation. Fifty-one NSCLC patients (mean age, 58.0 years) were included from 20 French centers: 61% were never-smokers and 59% were women. Among them, 82% had EGFR-activating mutations, 16% ALK translocations, or 2% ROS1 translocations. Before ICI therapy, patients had received a median of 3 treatment lines (including tyrosine-kinase inhibitor). The median PFS was 2.1 (95% confidence interval [CI], 1.5-3.2) months for the entire cohort, 2.2 (95% CI, 1.4-3.2) for EGFR-mutated patients, and 2.4 (95% CI, 2.1-not reached) months for ALK-translocated patients. The median OS was 14.7 (95% CI, 12.1-19.2) months for the entire population and 13.9 (95% CI, 8.8-20.0) and 19.2 (95% CI, 13.1-not reached) months for EGFR-mutated and ALK-translocated patients, respectively. Seven (13.7%) patients were treated with ICI for >9 months. Toxicities were reported in 22% (11/51), including 8% (4/51) grade ≥3. In this real-world setting, analysis of ICI PFS against EGFR-mutated or ALK-translocated NSCLC patients appeared close to that observed in pretreated unselected NSCLC patients. The more promising OS probably linked to post-ICI treatments. Large prospective studies on these patient subsets are needed. Abbreviations: ALK = anaplastic lymphoma kinase, ECOG PS = the Eastern Cooperative Oncology Group performance status, EGFR = epidermal growth-factor receptor, GFPC = French Lung Cancer Group, HR = hazard ratio, ICI = immune-checkpoint inhibitor, NSCLC = non-small-cell lung cancer, OS = overall survival, PFS = progression-free survival, ROS-1 = c-ros oncogene 1, TKIs = tyrosine-kinase inhibitors.