A 23-h affinity chromatography purification procedure for sorbitol dehydrogenase (L-iditol:NADl-oxidoreductase, EC 1.1.1.14) prepared from freshly excised rat liver has been developed that resulted in an 18% yield of an apparently homogeneous preparation (purification = 439-fold). The molecular weight of the enzyme was approx. 96 000. The enzyme was specific for NAD+ (NADH), but had no requirement for NADP+ (NADPH). The purified preparation shows significant activity with structurally related polyols and ketoses. Km values for sorbitol and fructose are 0.35 and 110 mM (at pH 7.1), respectively.