Purpose: A number of studies have provided concrete evidence about the role of Long noncoding RNAs (LncRNAs) in the development and progression of cancer. As such LncRNAs are believed to exhibit the potential to be used as therapeutic targets for the treatment of cancer. This study was undertaken to investigate the role and therapeutic implication of LncRNA PCAT29 in triple-negative breast cancer. Methods: breast cancer cell lines MDA-MB-231, MDAMB-436, BT20, HCC70 and HCC38 and non-cancer cell line MB157 were used in this study. Gene expression analysis was performed by qRT-PCR. Cell proliferation was monitored by MTT and colony formation assays. Apoptosis was detected by annexin Vipropidium iodide (PI) assay. Cell migration and Invasion was detected by wound heal and transwell assays. Results: The expression of LncRNA PCAT29 was significantly suppressed in the breast cancer tissues and the triple-negative breast cancer cell lines. PCAT29 overexpression caused inhibition of the proliferation rate and colony formation of the MDA-MB-231 cells. The proliferation of MD-MB-231 cells was inhibited by apoptotic cell death which was accompanied by elevation of Bax and depletion of Bd-2 expression. The wound healing assay showed that PCAT29 caused remarkable inhibition of the MDA-MB-23I cell migration. The transwell assay showed that PCAT29 overexpression resulted in 65% inhibition of the MDA-MB-231 cell invasion. Conclusion: PCAT29 regulates the proliferation, migration and invasion of breast cancer cells and may point to a novel therapeutic target in triple-negative breast cancer.