A number of N-substituted 2,3-dimethyl-3-arylpiperidines having an m- or p-arylhydroxyl were prepared and evaluated in rats for analgesic agonist and antagonist properties. The diastereomeric N-allyl and N-cyclopropylmethyl derivatives behaved as pure potent antagonists. Substitution of the arylhydroxyl from the m to the p position resulted in a net fall of the antagonist activity.