The invention relates to a method for the biotechnological production of xylitol, in which micro-organisms capable of metabolizing xylose to xylitol are used by modifying micro-organisms such that oxidation of NADH by enzymes other than the xylose reductase is reduced or excluded, cultivating the micro-organisms in a substrate containing xylose and 10-40 grams per liter of sulfite salt, and enriching the xylitol and recovering it from the substrate.