The prevalence rate of childhood obesity in Houston exceeds the national figures. Nutrition Mission, a 14-week health promotion and education intervention, was conducted to determine its feasibility and whether it would increase the nutrition and exercise (NE) knowledge of students in an elementary school. This novel student-initiated program used 44 medical students as volunteer instructors in 3 fifth-grade classrooms in a Houston, Texas, elementary school, in which most of the 35 students were socioeconomically disadvantaged and members of ethnic minorities. Research subjects completed pretests and posttests containing demographic, lifestyle, and knowledge-based multiple-choice questions regarding NE content. The Nutrition Mission intervention consisted of weekly programs between September 2007 and December 2007. Outcomes were measured by responses to NE lifestyle and knowledge questions. We found a significant increase in NE knowledge as a result of the intervention (68.1% compared with 78.1%, P<0.001). Subjects' gender and ethnicity affected responses to 2 lifestyle and 3 knowledge questions. The Nutrition Mission showed that a 14-week health promotion and education intervention conceptualized and implemented by medical students is feasible and can improve elementary school students' knowledge of NE. Future studies will include student volunteers from other health care professions and assess whether improved knowledge contributes to improved measurable health outcomes.