Background: Neoadjuvant EGFR-TKI therapy and customized adjuvant therapy are appealing but controversial strategy in patients with IIIA-N2 NSCLC. The purpose of this study was to evaluate the role of biomarker guided neo-adjuvant treatment strategy in patients with IIIA-N2 non-small cell lung cancer (NSCLC) stratified by epidermal growth factor receptor (EGFR) mutation status. Methods: Patients with resectable histologically documented stage IIIA-N2 NSCLC were assigned to either a neoadjuvant erlotinib arm or a gemcitabine/carboplatin (GC) arm based on EGFR mutation status (NCT00600587). The primary endpoint of this phase II study was response rate (RR). The secondary endpoints were progression-free survival (PFS) and overall survival (OS). Results: Twenty-four patients with IIIA-N2 NSCLC were enrolled in the trial from January 2008 until May 2011. The overall RR was 42%, and 58.3% (7/12) for the erlotinib arm with mutant EGFR, 25.0% (4/12) for the GC arm with wild-type EGFR (P = 0.18). Six cases in the erlotinib arm and seven cases in the GC arm received surgical resection. Median PFS was 6.9 months for the erlotinib arm and 9.0 months for the GC arm (P = 0.071). Median OS was 14.5 months for the erlotinib arm and 29.3 monthsfor the GC arm (P = 0.304). The median OS of the resected patients was 28.9 months for the erlotinib arm and 55.8 months for the GC arm (P = 0.218). In the overall population, the PFS and OS were 7.9 and 24.1 months, respectively. In addition, all six cases in the erlotinib arm that underwent resection gained partial response to tyrosine kinase inhibitor (TKI) re-treatment after progression, with a 2^nd median PFS of 11 months. Conclusions: Biomarker guided neo-adjuvant treatment strategy in patients with IIIA-N2 NSCLC is feasible. Erlotinib had a tendency to improve the response, while the benefit did not transfer to better PFS or OS in this subgroup. Further randomized controlled studies of neoadjuvant combined with adjuvant EGFR-TKI are required to establish the role of perioperative TKI therapy in patients with IIIA-N2 NSCLC. Clinical trial information: NCT00600587.