The physical educator's role is evolving into that of a teacher who is well educated in the areas of teaching, skill acquisition and development, motor learning, exercise physiology, physical conditioning, weight management, health, and lifestyle management. In an era when childhood obesity is at an all-time high, body composition can be one component of a physical education curriculum that is centered on the development of skills, lifetime physical activity, and health behaviors. Physical educators must be able to accurately assess body composition in children and adolescents, interpret the results correctly, discuss the results in an appropriate manner with students, and conduct meaningful research. This article provides relevant background information about body composition and its assessment as well as the interpretation of results in an appropriate context for physical educators. (Contains 3 tables and 2 figures.)