Patients with stage IIIA-N2 non–small cell lung cancer (NSCLC) have a wide range of postoperative outcomes. For this study, scientists discovered characteristics linked to postoperative survival and constructed a survival prediction tool. From January 2004 through December 2009, Researchers conducted a retrospective review of the Surveillance, Epidemiology, and End Results database. The backward stepwise technique was used to determine significant factors. Multivariable Cox regression was used to create the nomogram. The concordance index and calibration curve were used to assess the model’s performance. The training cohort consisted of 1809 individuals with stage IIIA-N2 NSCLC who underwent surgery. The backward stepwise technique identified age, sex, grade, histology, tumor size, visceral pleural invasion, positive lymph nodes, lymph nodes inspected, and surgical type (lobectomy vs. pneumonectomy) as significant predictive variables. The training cohort’s nomogram was generated and validated using an independent Chinese cohort. In the training cohort, the model’s concordance index was 0.673 (95% CI: 0.654-0.692), while in the validation cohort, it was 0.664. (95% CI, 0.614-0.714). The calibration plot revealed that the nomogram projected and observed survival were in perfect agreement. They found significant variations in survival across subgroups sorted by prognostic ratings in survival studies. This nomogram predicted individual survival following surgery for patients with stage IIIA-N2 NSCLC, which could help with patient and clinician survival counseling, clinical trial design and follow-up, and postoperative strategy-making.