We evaluated the relationship between interferon-induced transmembrane protein 1 (IFITM1) expression, epithelial-mesenchymal transition (EMT) signature and angiogenesis in lung adenocarcinoma. Additionally, we examined prognostic significance of IFITM1 according to pTNM stage to confirm that IFITM1 can serve as a complement to the pTNM stage. A total of 141 lung adenocarcinoma specimens were evaluated retrospectively by immunohistochemical staining for IFITM1, EMT markers (e-cadherin, β-catenin, and vimentin), and CD31 to measure microvessel density. IFITM1was expressed in 46.8% of the specimens. IFITM1 expression was significantly correlated with increased microvessel density (P = 0.048). However, IFITM1 expression was not associated with three EMT markers. In a multivariate analysis, IFITM1 was an independent prognostic factor for overall survival in a multivariate analysis (hazard ratio: 2.59, P = 0.01). Online database with data from 720 lung adenocarcinoma patients also revealed a negative prognostic significance of IFITM1 (P < 0.001). Furthermore, high IFITM1 expression was significantly correlated with decreased OS rates in each pTNM stage. IFITM1 is significantly correlated with angiogenesis and it may be used as a useful additional prognostic marker to aid pTNM classification.