A pharmaceutical composition comprising (R)-2-(2-aminothiazol-4-yl)-4′-{2-[(2-hydroxy-2-phenylethyl)amino]ethyl}acetanilide or a pharmaceutically acceptable salt thereof and (3R)-quinuclidin-3-yl (1S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline-2-carboxylate or a pharmaceutically acceptable salt thereof, as active ingredients, in particular for improving various symptoms accompanying overactive bladder, such as urinary urgency, pollakiuria and/or urinary incontinence.