Street names for Rohypnol tablets are Rophies, Ropies, Roofies, Ropes, Roches, Rochas, Rochas Dos, Rophs, Ropers, Ribs, R-25, Roach-2s, Trip and Fall, Remember All, Mind Erasers, Forget Pills, and the Date Rape Drug. An overdose of FZ gives an increased feeling of power and self-esteem, reduces fear and insecurity, and makes individuals believe everything is possible. FZ is also associated with loss of episodic memory and with impulsive violence, particularly when combined with alcohol. Subjects for the study were selected from a subpopulation of 47 male juvenile offenders in Swedish juvenile correctional institutions. Background information on subjects was obtained by in-depth interviews and personality inventories, including the Zuckerman Sensation-Seeking Scales, the Eysenck Personality Questionnaire, and the Karolinska Scales of Personality. Data concerning previous criminal offenses were obtained from the Swedish National Police Board. Almost all FZ abusers had been previously sentenced for serious violent offenses. Data suggested that FZ abused by psychiatrically vulnerable subjects, those with high scores on boredom susceptibility and verbal aggression, posed a serious hazard both to abusers and the community. Results support the view that FZ should be classified as a Schedule I drug, that is, a drug similar to heavy narcotics. 52 references, 3 tables, and 3 figures