OBJECTIVE The characteristics and efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) in advanced EGFR-mutant lung adenocarcinoma patients with primary tumor resection (PTR) is not yet clear. METHODS We enrolled advanced EGFR-mutant lung adenocarcinoma patients with EGFR-TKI as first-line therapy to access the impact of PTR on the outcomes. RESULTS A total of 466 patients were enrolled with 76 patients (16.3%) undergoing PTR; 59 patients recurred after curative surgery, while 17 patients underwent surgery as diagnostic purposes. PTR patients displayed a better performance status, a lower metastatic burden, and much less measurable diseases (30.3 vs. 97.4%, p < 0.001). PTR patients experienced a significantly longer progression-free survival (25.1 [95% CI 16.6-33.7] vs. 9.4 [95% CI 8.4-10.4] months; aHR 0.40 [95% CI 0.30-0.54], p < 0.001) and overall survival (56.8 [95% CI 36.3-77.2] vs. 31.8 [95% CI 28.2-35.4] months; aHR 0.57 [95% CI 0.39-0.84], p = 0.004). Survival advantage was still observed while comparing PTR patients with the better performance and lower metastatic burden subgroup found within the non-resection group. Moreover, the progression-free survival and overall survival of 11 patients who were found having pleural metastases during surgery and underwent PTR plus pleural biopsy, were also longer than those with pure N0--1/M1a-malignant pleural effusion disease in the non-resection group (n = 19) (p < 0.001 and p = 0.002, respectively). CONCLUSIONS PTR was associated with significantly better outcomes in advanced lung adenocarcinoma patients treated with EGFR-TKI. Further studies are needed to evaluate the biological role of PTR among these patients.