OBJECTIVE : To retrospectively investigate the safety and benefit of gefitinib plus transarterial infusion (TAI) therapy as a first-line treatment compared to gefitinib alone for patients with large (>7 cm) nonsmall cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. METHODS : Between January 2010 and December 2013, 92 consecutive treatment-naïve patients with large NSCLC with EGFR mutations, who were treated using gefitinib plus TAI (G+T, n = 42) or gefitinib alone (G, n = 50) were reviewed. The primary endpoints were the objective response rate (ORR) and tumor reduction rate. The secondary endpoints were progression-free survival (PFS) and overall survival (OS), and safety was also assessed. RESULTS : The baseline characteristics of the 2 groups were balanced, and no patients experienced treatment-related death. Toxicity outcomes did not differ between the G+T and G groups. The tumor reduction rate in the G+T group was significantly higher than that in the G group (42.9 vs 31.9%, P = .028). The ORR was 83% in the G+T group and 72% in the G group (P = .197). The median PFS was significantly longer in the G+T group than in the G group (14.0 vs 10.0 months, P = .023). The median OS was 30.0 months in the G+T group and 27.0 months in the G group (P = .235). CONCLUSIONS : This study suggests that compared with gefitinib alone, combination therapy with gefitinib plus TAI was well tolerated and potentially improved the tumor reduction rate and PFS in patients with large NSCLC with EGFR mutations.