MicroRNA research in humans and mammalian model organisms is in a crucial stage of development. Diagnostic and therapeutic values of microRNAs appear promising, but remain to be established. The physiological and pathophysiological significance of microRNAs is generally recognized, but much better understood in some organ systems and disease areas than others. In the present paper, we review several translational studies of microRNAs, including those showing the potential value of therapeutic agents targeting microRNAs and diagnostic or prognostic microRNA markers detectable in body fluids. We discuss the lessons learned and the experience gained from these studies. Several recent studies have begun to explore translational microRNA research in kidney disease and hypertension. Translational research of microRNAs in the kidney faces unique challenges, but provides many opportunities to develop and apply new methods, and to merge complementary basic and clinical approaches. © The Authors Journal compilation © 2012 Biochemical Society.