Twenty-seven studies were reviewed to determine whether school-based drug abuse prevention efforts have succeeded. Most of the studies reviewed either did not examine program impact on actual drug using behavior or were not designed with a degree of scientific rigor sufficient to warrant acceptance of their findings as valid. Those studies leading to reliable results regarding program effect on drug use were contradictory in their conclusions. In view of the possibility that educational efforts aimed at drug abuse prevention may be counterproductive, it is suggested that school-based programs henceforward be designed and conducted as experiments with controlled manipulation of relevant variables.