miRNAs belong to an important class of endogenous molecules which are present in a wide range of organisms including animals, plants and viruses. They are involved in regulating expression of several genes inside a cell due to presence of complementary region against specific mRNA molecules. Altered expression patterns cause progression of multiple diseases inside an organism. They have also been confirmed to be involved in different cancers including breast cancer. In this review, we discuss role of miRNAs with respect to uncontrolled division of cells, promotion, progression and metastasis in breast cancer.