Immunotherapy has paved the way for new treatment options for advanced non-small cell lung cancer (NSCLC). However, for patients who have progressed following first-line immunotherapy combined with chemotherapy, little is known about the benefits of the continuation of immunotherapy. Thus, the current study aimed to evaluate the efficacy of immunotherapy beyond progression (IBP) in patients with advanced NSCLC. A retrospective review of patients with advanced NSCLC who experienced disease progression after receiving a combination of ICIs and chemotherapy was conducted. Kaplan-Meier survival analysis was used to estimate progression-free survival (PFS) and overall survival (OS) times, and log-rank tests were employed to compare inter-group differences. Cox regression analyses were performed to identify independent factors associated with OS and PFS. In total, 136 patients who had disease progression after prior immunotherapy were included. A comparison of patients who were treated with ICIs after disease progression (IBP group) and those who received other treatments (non-IBP group) demonstrated a higher disease control rate after second-line treatment for the IBP group (89.8 vs. 70.8%, respectively; P=0.005). Kaplan-Meier curve analysis showed statistical differences in PFS2 (interval from the second-line treatment to progression or death for any reason; P=0.012) and OS (P=0.041). Subgroup analyses indicated superior clinical outcomes for the IBP group. Multivariate analyses revealed IBP to be an independent factor associated with improved PFS2 (hazard ratio, 0.613; 95% confidence interval, 0.403-0.933; P=0.022). In conclusion, favorable clinical outcomes for IBP were observed, and IBP remains a viable choice for patients with advanced NSCLC.