The effects have been evaluated of up to 30% (v/v) of methanol, ethanol, 2-propanol, tert-butylalcohol, dimethylsulfoxide, sulfolane, acetonitrile, dimethylformamide, N-methyl-2-pyrrolidone, hexamethylphosphoramide, tetrahydrofuran, dimethoxymethane, diglyme, and dioxane on horse liver alcohol dehydrogenase-catalyzed reduction of the representative ketone cyclohexanone. The most viable solvents are those shown in italics on the above list.