Liver metastasis has been found to affect outcome in prostate cancer and colorectal cancer, but its role in lung cancer is unclear. The current study aimed to evaluate the impact of de novo liver metastasis (DLM) on stage IV non-small cell lung cancer (NSCLC) outcomes and to examine whether tyrosine kinase inhibitors (TKI) reverse poor prognosis in patients with DLM and epidermal growth factor receptor (EGFR)-mutant NSCLC. Among 1392 newly diagnosed NSCLC patients, 490 patients with stage IV disease treated between November 2010 and March 2014 at Kaohsiung Chang Gung Memorial Hospital were included. Patients were divided into two groups according to DLM status. There were 75 patients in the DLM group and 415 patients in the non-DLM group. The DLM group included more patients with bone metastasis, fewer patients with a lymphocyte-to-monocyte ratio (LMR) > 3.1, and fewer patients with pleural metastasis. In the DLM group, Eastern Cooperative Oncology Group performance status 3-4 and LMR ≦3.1 were associated with poor outcome. In patients without DLM, overall survival (OS) was longer in patients with EGFR-mutant NSCLC than in those without (20.2 vs. 7.3 months, p < 0.001). Among DLM patients, OS was similar between the EGFR-mutant and wild-type EGFR tumor subgroups (11.9 vs. 7.7 months, p = 0.155). We found that DLM was a significant poor prognostic factor in the EGFR-mutant patients treated with EGFR-TKIs, whereas DLM did not affect the prognosis of EGFR-wild-type patients.