A psychometric study assessed the possibility of a preexisting personality configuration in students who became heavy drug users. We compared the MMPI profiles of 33 Carnegie Institute of Technology students who became heavy users of marijuana and hallucinogenic drugs and 33 peer control subjects. All subjects had been given the MMPI as entering freshmen in the years 1962-1965. The preuser sample constituted an avant-garde of drug-oriented counterculture in this setting. Profiles for both groups were well within normal limits yet unique in respective configurations. Preusers appeared to be socially skillful, adventorous, impulsive, and resistant to authority, while control subjects seemed less socially skilled, reserved, compulsive, and compliant. Significant scale differences appeared on Hy, Pd, and Ma, all being higher for preusers, and Es which favored the controls.