A process for the liquid phase adsorptive separation of 4,4'-dichlorodiphenylsulfone (4,4'-DCDPS) from crystallization residue feed mixture also containing other DCDPS isomers. The feed is contacted with an X or Y type zeolite, substituted with a cation of a Group IA or IIA metal or ammonium. The other isomers are selectively adsorbed to the substantial exclusion of 4,4'-DCDPS. The 4,4'-DCDPS is recovered in high purity by fractionating the raffinate to recover the desorbent, aliphatic alcohols having 4-8 carbon atoms either used alone or diluted with an aromatic compound.