BACKGROUND: Immunotherapy, monotherapy, and immunotherapy plus platinum-based chemotherapy are the standard treatments for advanced non-small cell lung cancer (NSCLC) patients with negative driver genes. However, the impact of similar continuing immunotherapy beyond progression (IBP) of first-line immunotherapy for advanced NSCLC has not yet been shown. This study aimed to estimate the impact of immunotherapy beyond first-line progression (IBF) and evaluate the factors associated with second-line efficacity. METHODS: Ninety-four cases of advanced NSCLC patients with progressive disease (PD) post first-line treatment with platinum-based chemotherapy plus immunotherapy and administrated prior immune checkpoint inhibitors (ICIs) between November 2017 and July 2021 were retrospectively analyzed. Survival curves were plotted using the Kaplan-Meier method. Cox proportional hazards regression analyses were applied to determine predictive factors independently associated with second-line efficacity. RESULTS: A total of 94 patients were incorporated in this study. Patients who continued the original ICIs after initial PD were defined as IBF (n=42), whereas those who discontinued immunotherapy were defined as non-IBF (n=52). The second-line objective response rates (ORR, ORR = CR + PR) of patients in the IBF and non-IBF groups were 13.5% 28.6%, respectively (P=0.070). No significant survival difference was found between patients in the IBF and non-IBF groups in first-line median progression-free survival (PFS) (mPFS1, 6.2 . 5.1 months, P=0.490), second-line median PFS (mPFS2, 4.5 . 2.6 months, P=0.216), or median overall survival (OS) (mOS, 14.4 . 8.3 months, P=0.188). However, the benefits inPFS2 were observed in individuals performed PFS1 >6 months (group A) than those of PFS1 ≤6 months (group B) (median PFS2, 4.6 . 3.2 months, P=0.038). Multivariate analyses did not reveal any independent prognostic factors for efficacy. CONCLUSIONS: The benefits of continuing prior ICIs administration beyond first-line immunotherapy progression might not be obvious in patients with advanced NSCLC, but those first line treatment showed a longer period may receive efficacy benefits.