Research has shown there is a decrease in physical activity among children as they age. Therefore, some adolescents are unhealthy, over weight, and unmotivated to participate in physical activity. The only physical activity most adolescents are exposed to during the day is their physical education class in school. When physical education programs are effective and adolescents are active, there can be changes in physical fitness indicators, overall health, and academic performance in school. One problem is that students participate in physical education for one semester and when class ends, they typically stop their physical activity and all benefits are lost. Physical education teachers are not equipped with the knowledge of how to provide motivational interventions that encourage students to continue to be physically active outside of class. There are numerous studies in sport psychology that provide evidence that motivational interventions work with adolescents. The purpose of this research was to examine the effects of an exercise psychology intervention aimed at motivating physical education students to be more physically active. It was hypothesized that students receiving a motivational intervention would have higher perceived competence and self-report levels of physical activity than students who did not receive the intervention. The design of the study included two groups of ninth grade students from six physical education classes. Group A participated in the intervention program for 10 weeks and a Fit for Life physical education class. Group B participated in an extended academic program and a Fit for Life physical education class. Data were collected at the beginning and end of the semester, with measures of demographic information, perceived competence to be active and level of physical activity outside of class. Motivational interventions included goal mapping, positive thinking, energy management, attentional focus and relaxation. One hundred and twenty adolescents (n=56 intervention, n=64 control), ages 14 to 18 years, participated in the study. Results indicated there were no pre-test differences between the groups in perceived competence or physical activity outside of class. Results for the post tests indicated that the students who received the intervention had significantly higher perceived competence to be active than the control group, F(2, 118) = 4.61, p < .034, however, there were no significant differences in physical activity level outside of class F(2, 118) = 1.21, p < .27. Strategies and implications for providing exercise psychology interventions in physical education are discussed.