Spindle- and disk-shaped pseudo-poly(methyl methacrylate) particles obtained by the surface-initiated atom transfer radical polymerization on alpha-Fe2O3 or Fe3O4 monodispersed fine particles exhibited lyotropic liquid-crystalline behavior in ionic liquids for a wide range of the mixing ratio. Effects of the size and shape of the particles on the lyotropic liquid-crystalline properties and the nanolevel self-organized structures have also been investigated.