Transformer 2β (Tra2β), a member of the serine/arginine-rich-like protein family, is an important RNA-binding protein involved in alternative splice. Deregulation of Tra2β has been observed in several cancers. However, the detailed role of Tra2β in non-small cell lung cancer (NSCLC) has not been elucidated. In this study, the contribution of Tra2β to NSCLC development was investigated. On histological level, the expression of Tra2β was determined by Western and immunohistochemistry assays. It demonstrated that Tra2β was expressed higher in NSCLC tumor tissues compared with adjacent non-tumor tissues. In addition to confirm the association of Tra2β expression with histological differentiation and clinical stage (p < 0.05), we also confirmed significant positive correlation between the expression level of Tra2β and that of Ki67 (p < 0.05, r = 0.446) by Spearman rank correlation test. Moreover, high expression of Tra2β predicted poor prognosis by Kaplan-Meier survival analysis. And Tra2β among with other clinicopathologic variables was an independent prognostic indicator for patients' overall survival by multivariate analysis. On cellular level, Tra2β expression was demonstrated to promote proliferation of NSCLC cells through a series of assays, including serum starvation and release assay, Western blot assay and flow cytometry analysis. Moreover, knockdown of Tra2β was confirmed to inhibit proliferation and to induce apoptosis of NSCLC cells through flow cytometry analysis, western analysis, cell counting kit-8 assay and Tunnel assay. Our results indicated that Tra2β was involved in the tumorigenesis of NSCLC and might be a potential therapeutic target of NSCLC.