This analysis examined differences in health instruction among teachers of required health education classes or courses who had received or wanted staff development on health topics, teachers who had a degree in health education, and teachers who were Certified Health Education Specialists. Classroom-level data were collected from teachers of a nationally representative sample of randomly selected classes in public and private elementary schools and randomly selected required health education courses in public and private middle/junior and senior high schools. Health topics analyzed included tobacco, alcohol, and other drug use prevention; accident or injury prevention; violence prevention; HIV, sexually transmitted disease, and pregnancy prevention; nutrition and dietary behaviors; and physical activity and fitness. Participation in and desire for staff development on health topics were low. Staff development on health topics during the 2 years preceding the study was associated with teaching more health topics; for most topics at the upper grade levels, this association was independent of whether health education topics were within health infused classes or separate health education courses. At the upper grade levels, courses taught by teachers with degrees in health education were associated with teaching all health topics examined; however, for most topics, this finding was not significant when health infused versus separate health education courses were controlled. (Contains 5 tables.)