With the novel microbial enzyme, 'arylalkyl acylamidase', optically active alpha-methyl arylalkylamines and alpha-methyl arylalkylalcohols have been obtained through enantioselective hydrolysis of their racemic amides and esters. (S)-Enantiomers of 1-methylbenzylamine, 1-methyl-3-phenylpropylamine and 1-methyl-3-phenylpropanol of high optical purity (> 94% e.e.) were synthesized with the cells of Nocardia erythropolis IAM 1440 or Cellulomonas fimi AKU 671. (R)-Enantiomer of 1-methyl-3-phenylpropylamine and (S)-enantiomer of 1-methyl-2-phenylpropanol of high optical purity (> 95% e.e.) were synthesized with the crude preparation of arylalkyl acylamidase of Pseudomonas putida Sc2 AKU 881.