This study addresses the hypothesis that YAP and TAZ have an overarching role in the transcriptional hierarchy in the smooth muscle of the urinary bladder by controlling myocardin expression. Using smooth muscle-specific and inducible deletion of YAP and TAZ in adult mice, we find that YAP and TAZ control myocardin expression, contractile differentiation, smooth muscle-specific splicing, and bladder contractility. These effects are largely independent of inflammation and chondrogenic differentiation.