Abstract: A method of optical enantiomer resolution by preferential crystallization involves entering, each time crystallization starts, the two-phase domain containing excess enantiomer and the saturated solution, and cooling according to a well-defined kinetic schedule. A racemic mixture of fine particle size is added to the mother liquors obtained after harvesting the crystals, the mother liquors then being heated to a temperature lower than that of homogenization of the solution so that excess enantiomer is present only in a solid state in equilibrium with the solution. Further cooling produces the other enantiomer and completes the cycle of operations which may then be carried out repetitively.