Drug addiction is a chronic and relapsing brain disorder characterized by compulsive drug seeking and continued drug use despite adverse consequences. The high prevalence and social burden of addiction is indisputable; however, the available intervention is insufficient. Abnormal gene expression is observed in reward-related brain regions in animal models of addiction. The modulation of gene expression and aberrant adaptation of neural networks attribute to the changes in brain function under repeated exposure to addictive drugs. The emerging recognition of the role of microRNA (miRNA) provides new insights into many biological and pathological processes in the central nervous system. Considerable studies have demonstrated that miRNAs are strong modulators of posttranscriptional gene expression in drug addiction. Here, we provide an overview of miRNAs, followed by evidence for aberrant miRNA expression and regulatory roles of miRNAs in drug addiction as well as neuroadaptation. We concluded by providing our perspectives that miRNAs have the potential as novel therapeutic targets for drug addiction.