MicroRNAs (miRNAs) are endogenous, non-coding small RNAs that regulate gene expression at the post-transcriptional level. Recent studies have shown that miRNAs are aberrantly expressed in various human diseases, ranging from cancer to cardiovascular hypertrophy. The expression profiles of the miRNAs clearly differentiate the normal from the pathological state and thus their potential as novel biomarkers in the diagnosis and prognosis of several human diseases is immense. Emerging data on the role of miRNAs in the pathogenesis of various human diseases have paved the way to test their ability to act as novel therapeutic tools. In the present review, we will explore the current knowledge about the role of miRNAs in various human diseases. In addition, we will focus on the emerging evidences demonstrating the potential of miRNAs as novel biomarkers and the strategies to use them as therapeutic tools.