Pharacologic therapy has been the mainstay of treatment for patients who have overactive bladder. In recent years, a number of new antimuscarinic agents have been introduced. Solifenacin succinate is a new once-daily antimuscarinic agent that is an effective and well-tolerated treatment option for patients who have overactive bladder. Solifenacin increases functional bladder capacity and decreases urgency, frequency, and incontinence. In pharmacokinetic studies, solifenacin demonstrated selectivity for the bladder over the salivary gland; thus, it is likely that the bladder selectivity of this agent is responsible for the low incidence of dry mouth and constipation reported in the clinical trials.