A process for producing propylene oxide, includes the steps of reacting propylene with hydrogen peroxide in the presence of a crystalline titanosilicate catalyst having a pore structure of a 12-oxygen-membered ring or more in an organic solvent as a medium capable of being separated from water solution, obtaining a reaction mixture containing propylene oxide, separating the reaction mixture into liquid phases to obtain a water layer and an oil layer containing the organic solvent, the propylene oxide thereby being separated from the water into the oil layer.