BACKGROUND Differing surgical series for the treatment of primary lung tumor with synchronous oligometastatic stage IV non-small cell lung cancer (NSCLC) have been published; however, outcomes remain ambiguous. METHODS Patients with synchronous oligometastatic stage IV NSCLC treated from 2005 to 2017 were enrolled to identify the impact of treatment sequence (primary lung resection vs systemic treatment) on progression-free survival (PFS) and overall survival (OS). RESULTS Tumor resection occurred in 51 patients (84% adenocarcinoma, 55% nonsmokers, and 65% driver gene mutation) before or after systemic treatment in 33 (64.7%) and 18 (35.3%) patients, respectively. Patients who received resection first were older (62.1 vs 54 years) and at a less advanced intrathoracic stage (18% vs 44%). No significant differences were noted regarding perioperative complications (30% vs 28%), hospital length of stay (9.0 vs 10.5 days), percentage of disease progression (91% vs 94%), overall death (70% vs 78%), median PFS (14.0 vs 22.8 months), and OS (44.6 vs 53.2 months). Patients with single-organ metastasis had significantly longer PFS and OS than those with oligometastases (17.5 vs 12.8 months, P = .040; and 55.6 vs 39.8 months, P = .035), respectively. Multivariable Cox analysis identified nonsolitary metastasis as the only independent predictor of PFS (hazard ratio, 2.27; 95% confidence interval, 1.07-4.81; P = .033). CONCLUSIONS Primary lung resection before or after induction systemic therapy may benefit patients with oligometastatic NSCLC. Future randomized clinical trials examining the effect of treatment sequence is recommended. (c) 2022 by The Society of Thoracic Surgeons