To clarify the potential biological function of miR-93 and its related molecular mechanism underlying metastasis in human hepatocellular carcinoma (HCC). miR-93 was significantly up-regulated in HCC tissues and was associated with poor 5-year overall survival in HCC patients. Transwell assays showed that over-expression of miR-93 increased HCC cell migration and invasion in vitro. Programmed cell death 4 (PDCD4) was a target gene of miR-93 and miR-93 could down-regulate the expression of PDCD4 by directly targeting its 3'-UTR. The re-expression of PDCD4 could attenuate the HCC cell invasion and migration induced by miR-93, while the knockdown of PDCD4 would promote HCC cell migration and invasion via the epithelial-mesenchymal transition (EMT) pathway. miR-93 provides new insight into the molecular mechanisms of pathogenesis and progression in HCC and offer a potential therapeutic target for the treatment of HCC patients.