Although numerous programs have been developed for Grade Kindergarten through 12 science education, evaluation has been difficult owing to the inherent problems conducting controlled experiments in the typical classroom. Using a rigorous experimental design, we developed and tested a novel program containing a series of pharmacology modules (e.g., drug abuse) to help high school students learn basic principles in biology and chemistry. High school biology and chemistry teachers were recruited for the study and they attended a 1-week workshop to learn how to integrate pharmacology into their teaching. Working with university pharmacology faculty, they also developed classroom activities. The following year, teachers field-tested the pharmacology modules in their classrooms. Students in classrooms using the pharmacology topics scored significantly higher on a multiple choice test of basic biology and chemistry concepts compared with controls. Very large effect sizes (up to 1.27 standard deviations) were obtained when teachers used as many as four modules. In addition, biology students increased performance on chemistry questions and chemistry students increased performance on biology questions. Substantial gains in achievement may be made when high school students are taught science using topics that are interesting and relevant to their own lives. (Contains 3 notes, 7 tables, and 2 figures.)