Micrometer-sized, monodisperse, "golf ball-like" particles that have numerous dimples at the surfaces were prepared by seeded dispersion polymerization of n-butyl methacrylate (n-BMA), with polystyrene/poly(styrene-co-sodium styrene sulfonate) composite particles as seed, in the presence of dodecane droplets in a methanol/water (80/20, w/w) medium, followed by the evaporation of dodecane. The dimples at the surface were formed by the volume reduction of poly(n-BMA)/dodecane (Pn-BMA/dodecane) domains, because of the evaporation of the dodecane. The size and number of dimples at the Surfaces of the obtained golf ball-like particles decreased as the sodium styrene sulfonate content of the seed particles increased. The Pn-BMA/dodecane domains were engulfed deeper in the surface layer of the seed particle, and, thus, dimples became apparently smaller at the surface with an increase in the hydrophilicity of the surface of the seed particle.