Purpose: The purpose of this study is to examine the expression and clinical significance microRNA-383 (miR-383) in non-small cell lung cancer (NSCLC) both in vitro and in vivo. Methods: Tumorous miR-383 expressions were compared between NSCLC cell lines and normal lung cells. MiR-383 was upregulated in A549 and H596 cells to evaluate its tumor suppressive effect on NSCLC proliferation, invasion and migration in vitro. MiR-383 expression was also compared between 139paired clinical NSCLC tissues and their adjacent non-carcinoma lung tissues, as well as between earlystage NSCLC tissues and advanced-stage NSCLC tissues. Correlation between tumorous miR-383 expression and NSCLC patients' clinicopathological features and overall survival (OS) were also statistically analyzed. Results: MiR-383 was significantly downregulated in NSCLC cell lines. MiR-383 overexpression reduced proliferation, invasion and migration of A549 and H596 cells. In clinical samples, miR-383 was also found to be markedly downregulated in NSCLC carcinomas than in non-carcinoma lung tissues, and in advanced-stage carcinomas than in early-stage carcinomas. It was also found low tumorous miR-383 expression was significantly associated with NSCLC patients' poor prognosis, including advanced TNM stages, positive lymph node metastasis, and shorter OS. Conclusion: Endogenous miR-383 is a functional tumor suppressor in NSCLC. It may also serve as an independent prognostic factor for patients with NSCLC. (C) 2016 Elsevier Masson SAS. All rights reserved.