Since the profession of public health began, public health professionals have focused on one’s individual knowledge and attitudes as the main determinant of health behavior. Professionals did not account for the social, cultural, and economic circumstances that influence health behavior. As a result, forms of the social ecological model were introduced by sociologists after WWI to further understand the relationship between environmental factors and behavior. In the 1970s and 1980s a conceptual model was introduced. This model was made up of five levels; Intrapersonal, Interpersonal, Community, Organizational, and Public Policy. The intrapersonal level involves the attitudes and skills that an individual possesses, and it can also include an individual’s age, race, gender, and religion. The interpersonal level is the social network surrounding an individual, this includes friends, family and coworkers. The next level, community, is the relationship among organizations. The organizational level includes institutes with rules and regulations that can affect an individual or group; this level includes schools and workplaces. Lastly, public policy regards the laws and regulations the government puts in place. Examples of such regulations include taxes, as well as bans on certain items. In this chapter, we will examine each level as it pertains to health behavior. Furthermore, we will see how the social ecological model can be utilized to make successful public health interventions.