MicroRNAs are novel small noncoding RNA molecules that regulate gene expression at the post-transcriptional level. Compelling evidence reveals that there is a causative link between microRNAs deregulation and cancer development and progression. The present study aims to explore the function of miR-206 in the proliferation, apoptosis, motility, and invasion of nonsmall cell lung cancer. Using real-time PCR, we detected the miR-206 expression of normal lung tissues, tumor tissues, human normal bronchial epithelial cell line, and six lung cancer cell lines (LCCLs). Then, we evaluated the role of miR-206 in cell proliferation, apoptosis, and invasion using Cell Counting Kit-8 assay, Annexin-V/FITC assay, wound healing, and Transwell assay in LCCLs. As a result, miR-206 expression level was lower in high metastasis tumors and 95D than low metastasis tumors and normal lung tissues as well as other LCCLs. After miR-206 was upregulated in LCCLs, cell proliferation was notably attenuated and apoptosis was significantly increased. Furthermore, overexpression of miR-206 inhibited migration and invasion of lung cancer cells. In conclusion, our data suggest that expression level of miR-206 was inversely correlated with metastatic potential of lung cancer. Anat Rec, 2010. © 2010 Wiley-Liss, Inc.