DEAD-box RNA helicase 3 (DDX3) is a highly conserved family member of DEAD-box proteins in all eukaryotes from yeasts to human beings. Accumulating studies have confirmed DDX3 has the ability to regulate different steps of RNA metabolism, including RNA splicing, RNA export, transcription and translation initiation. Moreover, DDX3 is involved in many biological processes, such as stress response, cell apoptosis, cell cycle regulation and virus infection. In recent years, DDX3 is getting increasing attention due to its essential roles in cancer progression. However, DDX3 role in cancer development is rather complicated. This review mainly focuses on the dual roles of DDX3 and DDX3-mediated signaling pathways in multiple cancers. In addition, the interplaying causes for the controversial roles of DDX3 in cancer are discussed. So far several small molecular chemical compounds targeting DDX3 are also summarized from the anticancer activity to the clinical trials of DDX3 inhibitors.