Drug and alcohol use among youth remains pervasively high, but students are receiving less school-based prevention. Infusing health information into core curricula may be a valuable prevention approach. Therefore, behavior change theory was used to develop a science education curriculum on drugs for fourth- and fifth-grade students, which was then evaluated using a pretest/posttest quasi-experimental design. Exposure to the curriculum was associated with a change in knowledge; other characteristics such as grade level played a role. More positive attitudes toward science at pretest predicted greater knowledge change, and students who knew less at the start showed a greater change in knowledge. Results of this evaluation may support the efficacy of the curriculum and the utility of combining behavior change theory with educational approaches. (Contains 1 figure and 4 tables.)