Lung cancer is the most frequent cancer in China and all over the world. Recent studies have shown that long noncoding RNAs play critical roles in multiple biological processes including oncogenesis. In this study, we reported a new lncRNA GAS6-AS1 (GAS6 antisense RNA 1), whose expression was downregulated in tumor tissues in 50 patients with non-small cell lung cancer (NSCLC) compared with those in the adjacent normal tissues (P < 0.001). Furthermore, decreased GAS6-AS1 expression was negatively correlated with lymph node metastasis (P = 0.032) and advanced tumor node metastasis stage (P = 0.003). Univariate and multivariate analyses showed that GAS6-AS1 expression served as an independent predictor for overall survival (P = 0.036). Also, GAS6-AS1 level was inversely correlated with GAS6 (growth-arrest-specific gene6) mRNA level (Pearson's correlation -0.620). In conclusion, our study demonstrated that altered lncRNA GAS6-AS1 expression might be involved in the development and progression of NSCLC by influencing its host gene and promised to be a potential diagnostic target in patients with NSCLC.