Twenty-three chapters of the American Red Cross located in the Northeast participated in this study of achievement in adult cardiopulmonary resuscitation (CPR) classes. Sixty-eight classes offered to the public were studied by a pencil-and-paper survey and a specially developed written test. This study locates student, instructor, and course factors associated with achievement in CPR classes. Student factors found to be significant predictors of achievement were reading difficulty, age, and prior CPR training. The only instructor factor to predict student achievement was training within the 12 months prior to teaching the studied class. Showing a videotape to the class and distributing workbooks before the class also had a significant positive effect on student achievement. The addition of material by the instructor decreased achievement.