A method for isolation of 1,3-propanediol from post-fermentation broth is disclosed. The method generally involves the following steps: (1) biomass removal from post-fermentation broth by one of the following methods: ultrafiltration, filtration, centrifugation or sedimentation; (2) 1,3-propanediol extraction with organic solvent mixture containing 2-butanone with high efficiency performed continuously or stepwise; (3) distillation under vacuum to obtain highly pure target product and (4) organic solvent recovery and recycling the solvent back into the process. The method is useful for recovering valuable 1,3-propanediol from aqueous solutions produced by fermentation.