Sedentary living and obesity across all age, social, ethnic, and economic categories has reached epidemic proportions in the United States. Recent data from the CDC (2004) showed that between 1980 to 2002, the rate of obesity among children aged 6-11 climbed from seven to 16% and among adolescents aged 12-19 it tripled from five to 16%. Youth sport has been seen as one potential medium that could promote more physical activity and play a major role in improving children's overall health. While on the surface there appears to be an obvious relationship between participation in youth sport and increased health benefits, further examination reveals that the outcomes associated with youth sport participation are often contradictory. For example, Louv (2005) indicates that the increase in child obesity has “coincided with the greatest increase in organized sports for children in history” (p. 47). The most apparent explanation may be that participation in youth sport has declined significantly among both boys and girls during middle school years (President's Council on Physical Fitness and Sport, 1997). Although the drop-out rate from sport increases among 11-13 year old age group (see Petlichkoff, 1996) middle schools have consistently been an understudied setting for examining physical activity patterns (McKenzie, 2001). To counteract these issues, the Committee on Prevention of Obesity in Children and Youth (Koplan, Livermore, & Kraak, 2005) recommended that intramural sports be more widely introduced within schools in order to meet the needs of students with a wide range of abilities who lack time, skills or confidence to participate in interscholastic sports. This study examined the role of school based intramural program in facilitating immediate and long term positive impact on physical activity, healthy behavior, and obesity in children. A self –report psychological measure based on the theory of planned behavior (Ajzen, 1985; 2001), designed to assess intentions toward continuing to participate in a current activity(s) was administered to 500 middle school students. Path analysis was conducted to examine the relationships between attitudes, subjective norms, perceived behavioral control and the prediction of intention to participate in sports. Demographic variables based on the model (differences between gender, ethnicity and SES as well as non participants and participants of intramural sports) were further examined. The results of the model help us to further understand what explains intention toward physical activity which in turn has been found to predict actual behavior.Keyword(s): exercise/fitness/physical activity, intramurals, middle school issues