Background The role of pneumonectomy after neoadjuvant therapy for stage IIIA non-small cell lung cancer (NSCLC) remains uncertain. Methods Patients who underwent pneumonectomy for clinical stage IIIA NSCLC were abstracted from the National Cancer Database. Individuals treated with neoadjuvant therapy, followed by resection, were compared with those who underwent resection, followed by adjuvant therapy. Logistic regression was performed to identify factors associated with 30-day mortality. A Cox proportional hazards model was fitted to identify factors associated with survival. Results Pneumonectomy for stage IIIA NSCLC with R0 resection was performed in 1,033 patients; of these, 739 (71%) received neoadjuvant therapy, and 294 (29%) underwent resection, followed by adjuvant therapy. The two groups were well matched for age, gender, race, income, Charlson comorbidity score, and tumor size. The 30-day mortality rate in the neoadjuvant group was 7.8% (57 of 739). Median survival was similar between the two groups: 25.9 months neoadjuvant vs 31.3 months adjuvant (p = 0.74). A multivariable logistic regression model for 30-day mortality demonstrated that increasing age, annual income of less than $35,000, nonacademic facility, and right-sided resection were associated with an elevated risk of 30-day mortality. A multivariable Cox model for survival demonstrated that increasing age was predictive of shorter survival and that administration of neoadjuvant therapy did not confer a survival advantage over adjuvant therapy (p = 0.59). Conclusions Most patients who require pneumonectomy for clinical stage IIIA NSCLC receive neoadjuvant chemoradiotherapy, without an improvement in survival. In these patients, primary resection, followed by adjuvant chemoradiotherapy, may provide equivalent long-term outcomes.