A process for producing sugar alcohols having six carbon atoms, which comprises hydrogenating ketohexose, such as psicose, tagatose, sorbose and the like, in the presence of a catalyst containing a metal selected from the elements belonging to the eighth family in the periodic table, such as nickel, ruthenium, platinum, palladium and the like, is provided. According to this process, sugar alcohols having six carbon atoms can be produced efficiently at a large amount, the separation and recovering of the catalyst after completing the reaction are facilitated, and sugar alcohols having a desired production ratio can be produced efficiently.