BACKGROUND Long non-coding RNA PCAT7 has been revealed to participate in tumorigenesis of various cancers. However, the mechanism of PCAT7 in non-small cell lung cancer (NSCLC) has not been identified. Hence, this study aimed to determine the function of PCAT7 in NSCLC. MATERIAL AND METHODS The expression level of PCAT7 in 96 pairs of NSCLC tissues and 6 cell lines was detected by qRT-PCR. Proliferation assay, flow cytometric analysis, transwell/migration assay, and Western blotting assay were performed to detect the relation between PCAT7 and malignant behaviors of NSCLC cells in vitro, including cell proliferation, apoptosis, migration, invasion, and epithelial-to-mesenchymal transition (EMT). Rescue assays were carried out to confirm the contribution of PCAT7 to the progression of NSCLC cells by targeting miR-134-5p. RESULTS PCAT7 was found to be overexpressed in NSCLC tissues (compared with corresponding non-tumor tissues) and NSCLC cells (compared with normal cell line 16-HBE). Overexpression of PCAT7 resulted in the promotion of tumor cell proliferation, inhibition of cells apoptosis, facilitation of cells metastasis, and formation of EMT phenotype, while PCAT7 expression deletion remarkably prohibited cell proliferation, accelerated their apoptosis, weakened metastasis, and reversed EMT to MET. miR-134-5P, as a target gene of PCAT7, restored the effects of down-regulation of PCAT7. CONCLUSIONS These findings demonstrate that PCAT7 participates in tumor progression in NSCLC by inhibiting miR-134-5p.