Mirabegron is a novel, once-daily, orally active, first-in-class, potent β₃-adrenoceptor agonist recently approved by Food and Drug Administration for overactive bladder therapy. Phase II studies and four large-scale phase III multinational randomized, controlled trials have supported the efficacy and tolerability of mirabegron in the clinical trial setting of patients with overactive bladder for up to 12 weeks of therapy and in the long term (12 months). The reported incidence and severity of treatment-emergent and serious adverse effects were similar to antimuscarinics, but with a more than threefold lower incidence of dry mouth compared with tolterodine. However, the effects on the cardiovascular system, pharmacokinetic interactions with other drugs, and increased incidence of new malignant events will require careful evaluation in the near future.