Significance: Cautionary use of dietary supplements has begun to receive heightened attention nationwide, and increasingly health educators are being asked about dietary supplements and their efficacy. The purpose of this field study is to identify the factors that influence the use of dietary supplements marketed as nutritional ergogenic aids (DSMNEA) among adolescent athletes and to describe the role of health education related to this topic. Design: The study surveyed 1,735 student athletes (male, n=1014; female, n=721) ranging from Grade 9 to Grade 12 and aged 14 to 19 years. The students were from nine public middle and high schools. Selected classes from each school were surveyed; all students in these classes were eligible to participate in the study. The response rate was over 90%. Results: Half (50.4%) of the respondents reported having ever used DSMNEA, such as creatine, chromium picolinate, and androstenedione. The students most likely to report currently taking one or more DSMNEA were male (29.3%) and participants in wrestling (36.4%), baseball (32.6%), or track (29.2%). Among current users, gaining muscle size (52.4%), looking better (45.6%), supplying energy (43.8%), and playing sports better (36.8%) were the most common reasons for taking DSMNEA. Male users were most likely to report gaining weight and muscle size, playing sports better, and losing body fat as reasons for use. Females were more likely to report supplying energy, losing weight, and gaining strength as their reasons for use. Implications for health educators and their role in the development and evaluation of targeted prevention and intervention strategies are discussed from a social-ecological perspective to begin to establish “best practice” guidelines related to DSMNEA. Keyword(s): health promotion, high school issues, youth sports