The present invention relates to a process for the purification of 1,3-propanediol from a fermentation medium of a 1,3-propanediol-producing microorganism, comprising 1,3-propanediol and fermentation coproducts consisting at least of glycerol, wherein the 1,3-propanediol-producing microorganism is separated from the other components of the fermentation medium to give a clarified aqueous solution, clarified aqueous solution is passed over a cation exchange resin to give at least one fraction comprising purified 1,3-propanediol and at least one fraction comprising the fermentation coproducts, and the 1,3-propanediol is recovered.