MicroRNAs (miRNAs) are small non-coding RNAs, involved in regulation of post-transcriptional gene expression. They exert key role not only in physiology and normal development of the cardiovascular system but also in cardiovascular disease development and progression. Recent animal and human studies of tissue specific miRNAs have suggested a role in structural and electrical remodeling in atrial fibrillation (AF). Their emerging role as biomarkers and potential therapeutic targets in patients with AF is discussed in this review.