Drug-use myths, questionable beliefs regarding the effects of drug use, may help to explain why people engage in self-injurious drug-use behavior. While clinicians and applied social researchers have used this concept of drug-use myths extensively when developing substance abuse prevention or cessation programs, drug belief-type myth measures have not been investigated empirically. The present study examined the internal consistency and discriminant validity of a drug-use myth measure among 362 continuation (alternative) high school youth and found it to be discriminable from demographic, drug use, and other psychosocial measures. Controlling for its relations with its correlates, social desirability, perceived friends' drug use, ethnicity items, and gender, the myth measure remained significantly associated with 4 drug-use measures. Future research regarding drug use myths as predictors of drug use is encouraged based on these results.