MicroRNAs (miRNAs) are endogenous, short (~22 nucleotide), evolutionarily conserved, non-coding RNAs that regulate gene expression at the post-transcriptional level. Recent evidence suggests that miRNAs are differentially expressed in the failing myocardium and play an important role in progression of heart failure by targeting genes that govern diverse functions in cardiac remodeling process including myocyte hypertrophy, excitation-contraction coupling, increased myocyte loss, and myocardial fibrosis. In addition to their role in adverse cardiac remodeling, miRNAs hold promise as biomarkers of disease progression in heart failure given their presence in circulation and enhanced stability. Further development of miR-based therapeutics may allow for modulation of cardiac and/or systemic levels of specific miRNAs in patients with heart failure . Here, we summarize current knowledge of miRNAs in relation to their role in regulating various aspects of the cardiac remodeling process and discuss their potential use as biomarkers and/or therapeutic targets in heart failure.