Neurogenesis, the process of generating functional neurons from neural stem cells, is tightly controlled by many intrinsic and extrinsic mechanisms. Uncovering these regulatory mechanisms is crucial for understanding the functions and plasticity of the human brain. Recent studies in both invertebrates and vertebrates point to the importance of small regulatory RNAs in regulating lineage-specific gene expression and determining neuronal identity during neurogenesis. These new observations suggest that small regulatory RNAs could function at many levels to regulate self-renewal of neural stem cells and neuronal fate specification, implicating small regulatory RNAs in the complexity of neurogenesis.