Objective To explore the impact of nonsteroidal anti-inflammatory drugs (NSAIDs) on clinical efficacy, toxicity and prognosis in non-small cell lung cancer after immunotherapy. Methods The clinical data of patients with advanced non-small cell lung cancer who received immunotherapy in our hospital from January 2019 to March 2021 were retrospectively analyzed. Patients were divided into NSAIDs group (n=79) and Non-NSAIDs group (n=86) according to whether NSAIDS were used within 42 days before or after immunotherapy. Objective response rate (ORR) and disease control rate (DCR) were compared between the two groups. Kaplan-Meier method was used to calculate overall survival (OS) and progression-free survival (PFS). Univariate and multivariate analyses of prognostic factors were performed by COX proportional hazard regression model. Results The ORR of patients in NSAIDs group was higher than that patients in Non-NSAIDs group ( 73.40% vs 58.10%, P=0.039), and there was no difference in DCR between the two groups (96.20% vs 93.00%, P=0.369). There was no difference in the incidence of grade 3 or higher immune-related adverse events between the two groups (2.50%, vs 4.70%, P=0.683). The median PFS (16 months vs 15 months, P=0.021) and OS (25 months vs 21 months, P=0.027) of patients in NSAIDs group were higher than those in Non-NSAIDs group. Both univariate and multivariate analyses suggested that the use of NSAIDs were factors influencing the OS and PFS of patients with advanced non-small cell lung cancer who received immunotherapy. Conclusion Among patients with non-small cell lung cancer receiving immunotherapy, patients using NSAIDs had a higher objective response rate. NSAIDs is good prognostic factors in patients with non-small cell lung cancer after immunotherapy