Knowledge of health behavior theory allows health practitioners to design health promotion interventions that are based on factors that influence behavior. Objectives: At the conclusion of this lesson, students will be able to: (1) identify and define the three major levels of influence of the Ecological Perspective, (2) identify how each level of the Ecological Perspective impacts the health of community members described in an enclosed case study, and (3) develop an intervention strategy to improve the health of community members described in the enclosed case study. Target Population: Because the application of health behavior theory is a topic pertinent to numerous disciplines, individuals studying health education, health promotion, public health, evaluation and assessment, and social work may benefit from this lesson. (Contains 3 figures.)