Monodisperse hydrogel particles were prepared by membrane emulsification using ordered anodic porous alumina. The size of the obtained hydrogel particles could be controlled by changing the pore size in the anodic porous alumina. The average diameter of the obtained hydrogel particles showed a good linear relationship with the pore size of anodic porous alumina used for membrane emulsification. The process is simple and allows for the high-throughput preparation of monodisperse hydrogel particles with controlled sizes.