Abstract: MicroRNA (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. In the brain, microRNAs are abundant and their expression profiles are changed by neuronal activation in response to behavioral training or chemical/electrical stimulation. These dynamic changes at miRNA level regulate the expression of genes required for cognitive processes such as learning and memory. In addition, in cognitive dysfunction such as dementia, miRNAs are perturbed, and targeted regulate many genes and pathways so that function in the occurrence and development of diseases. This review will summarize the role and related mechanisms of miRNAs in cognition and discuss its potential applications in cognitive dysfunction diseases.