A recent bioinformatics analysis identified long non-coding RNA antisense 1 ADAMTS9-AS1 as an independent prognostic marker in several tumors, including prostate cancer and bladder cancer. Nevertheless, the prognostic value and functional role of ADAMTS9-AS1 in non-small cell lung cancer (NSCLC) remain elusive. Here, we first found that the expression of ADAMTS9-AS1 was significantly upregulated in NSCLC tissues compared with adjacent normal tissues using quantitative real time PCR analysis. Clinically, we observed that ADAMTS9-AS1 expression was associated with TNM stage, lymph node metastasis and poor prognosis in NSCLC patients. By performing loss-of-function assay in A549 and 95D cells, our in vitro experiments further showed that knockdown of ADAMTS9-AS1 remarkedly suppressed cell proliferation, caused cell cycle G0/G1 arrest and apoptosis, and inhibited cell migration and invasion in NSCLC cells using CCK-8, colony formation, flow cytometry and transwell assays. Moreover, we found that ADAMTS9-AS1 knockdown downregulated the expression of CDK4, N-cadherin, Vimentin, but upregulated the expression of Bad and E-cadherin. In summary, our results revealed that ADAMTS9-AS1 may serve as a potential therapeutic target for the treatment of patients with NSCLC.