A series of polymer microspheres was prepared via solvent evaporation by dispersing dichloromethane solutions of polylactic-co-glycolic acid (PLGA) in water. The dimensions of the final dry particles were measured by laser diffraction and correlated to the main fluid-dynamic parameters of the dispersion process, namely viscosity ratio, volume fraction of dispersed phase, intensity of stirring, and Weber number (We). Data analysis indicated that the system under study can be quantitatively well described by empirical models present in the literature and concerning the dispersion of liquid-liquid immiscible systems. The PLGA microspheres obtained in this way may be employed for fabrication of biodegradable scaffolds for tissue engineering.