To study the association of positive expression of nucleotide excision repair cross complementary group 1 (ERCC1) in the tumor tissues with platinum resistance of the tumor cells and the clinical outcomes of neo-adjuvant chemotherapy in elderly patients with non-small cell lung cancer (NSCLC).ERCC1 expression was detected immunohistochemically in the tumor tissues from 113 elderly patients with NSCLC, of which 58 patients received platinum-containing neo-adjuvant chemotherapy, and the impact of ERCC1 expression on the outcomes of neo-adjuvant chemotherapy was analyzed.The total positivity rate of ERCC1 expression was 35% in these patients. The positivity rates was significantly higher in the patients receiving neo-adjuvant chemotherapy than in the control group (46.7% vs 21.05%, χ² = 3.770, P = 0.048). In the 39 patients positive for ERCC1, the response rate to treatment was 53.85%, as compared to the rate of 51.35% in the 74 ERCC1-negative patients. After neoadjuvant chemotherapy, the median survival time (MST) was 53 months in ERCC1-negative patients, as compared to 37 months in the positive patients. The ERCC1-negative and ERCC1-postivie patients showed similar 3- and 5-year survival rates (48.3% vs 44.4%, χ² = 0.033, P = 0.856; 22.5% vs 18.5%, χ² = 0.096, P = 0.757). Multivariate COX regression analysis showed that ERCC1 expression level in the tumor tissue and TNM stages were independent factors that affected the prognosis of the patients (P < 0.05).Neoadjuvant chemotherapy can induce ERCC1 expression in the tumor, and the objective response rate of neoadjuant chemotherapy can be low in NSCLC patients with high ERCC1 expression. ERCC1 expression is an independent factor affecting the prognosis of elderly patients with NSCLC receiving neoadjuant chemotherapy.