This study focuses on 19 juvenile offenders who were frequently intoxicated by flunitrazepam (FZ), almost exclusively under the brand name Rohypnol. 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 provides the belief that everything is possible. FZ is also associated with loss of episodic memory and with impulsive violence, particularly when combined with alcohol. The subjects were taken from a subpopulation of 47 male juvenile offenders from Swedish national correctional institutions. Background information for subjects was obtained by in-depth interviewing and personality inventories including the Zuckerman Sensation-Seeking Scales, the Eysenck Personality Questionnaire, and the Karolinska Scales of Personality. Data concerning previous criminal offenses was obtained from the Swedish National Police Board. Almost all of the FZ abusers had been previously sentenced for serious violent offenses. Our data suggest that FZ abused by psychiatrically vulnerable subjects (i.e., with high scores on boredom susceptibility and verbal aggression) poses a serious hazard both to the abusers as well as the community. Our results support the finding that FZ should be classified as a Schedule I drug (i.e., a drug similar to heavy narcotics).