MicroRNAs (MiRNAs) are small non-coding RNAs able to regulate gene expression at a posttranscriptional level. Recent evidence indicates that they play a crucial role in the initiation and progression of human cancers. In this review we briefly describe microRNA biogenesis and function, giving a more detailed account of the current state of knowledge concerning the role of microRNAs in brain tumors and stem-like tumor cells. MicroRNAs control brain tumor development by regulating multiple biological characteristics such as proliferation, invasion, differentiation and angiogenesis. Research in this field is rapidly spreading and encourages potential applications of microRNAs as diagnostic and prognostic tools, in addition to therapeutic targets and tools, to grant clinical benefits to patients suffering of brain tumors.