Positively charged monodisperse particles have been synthesized via emulsifier-free emulsion copolymerization of methyl methacrylate with vinylformamide and ethylene glycol dimethacrylate. The effect of the cross-linking agent on the conversion of the monomers, as well as on the shape, size distribution, and surface characteristics of the obtained particles, has been determined. Addition of the cross-linking agent (5 wt %) to the reaction system has been shown to result in the formation of particles, which, after hydrolysis, have positive ζ potentials at pH 2–10.