Noncovalent complexes were formed by lyophilization of aqueous solutions containing horse liver alcohol dehydrogenase, NAD(+) and a polymer [ethyl cellulose or poly(vinyl butyral)]. The complexes expressed higher specific catalytic activity in organic solvents as compared to a corresponding amount of enzyme deposited on to Celite or lyophilized enzyme powder. The noncovalent complexes were soluble in toluene. In butyl acetate and methyl t-butyl ether, suspensions of fine particles were formed.