Introduction: Atezolizumab represents a therapeutic option in patients with NSCLC previously treated and anti-PD-1/PD-L1-naive. We aimed to assess which patients benefit most from atezolizumab. Methods: We retrospectively analyzed patients with NSCLC, who had received ≥1 previous cytotoxic chemotherapy regimen. Patients with EGFR or ALK genetic alterations had previously received TKI therapy. Disease control was considered if there was stability or objective response. Results: We studied 39 cases, 74.4% were male, with median age of 66 (57-70) years, 71.8% had smoking exposure and 74.4% had an ECOG 0-1; 64.1% were adenocarcinoma and 35.9% squamous cell carcinoma. Concerning staging, when anti-PD-L1 was started, 64.1% had stage IV disease, 33.3% stage III and 2.6% stage IIB. Twenty-five (67.6%) patients expressed PD-L1 of ≥ 1% and 45.8% had driver mutations. After diagnosis, the median time until atezolizumab was 12 (7-21) months, and median duration of atezolizumab was 2 (1-5) months. Disease control was obtained in 15.4% of the cases, 69.2% had disease progression and in 15.4% of patients the response was not assessed. The median overall survival was 18 (10-26) months and was longer in cases with disease control (p=0.001), for patients not-stage IV at diagnosis (p=0.023), and lower for patients with multiple metastatic lesions (p=0.024). Adjusting survival for age, histology, smoking, constitutional symptoms, ECOG and disease control; disease control was the only factor whose association remained statistically significant. Conclusion: In our series, only 15% of patients had a clear benefit with atezolizumab as second-line therapy. Stabilization and disease response were the only markers of survival benefit.