Mirabegron is a relatively new drug introduced to treat overactive bladder syndrome. It can be used either on its own or as part of a combination. This drug has been extensively studied, with a good number of Phase II and Phase III trials showing promising outcomes. These studies show that mirabegron is an effective, well-tolerated drug, which could have some adverse effects of concern. In this review, we look at the trials on mirabegron, as well as its pharmacokinetics, mechanism of action, and side effects as documented in the literature.