The social cognitive theory of human behavior stipulates that individuals are able to self-regulate, adopt goals, use anticipatory forethought, and reflect on their own feelings, thoughts and behaviors (Bandura, 1997). This study uses a social cognitive theory (the theory of planned behavior [TPB], Ajzen, 1991) to investigate the influence of professional development on teachers' intentions and behaviors related to teaching a statewide curriculum (i.e., the Exemplary Physical Education Curriculum [EPEC]). The theory states that attitudes, important others' beliefs, and control may predict intentions and subsequently intentions may predict behaviors. The purpose of this quasi-experimental field study was to determine if professional development training in EPEC resulted in increases in teachers' intentions to teach the EPEC curricular content related to “fitness activity” and “activity-related knowledge” as well as if they taught more content across an academic year. Forty-seven teachers who had previously received EPEC training participated. Two groups of teachers (Mentors, n =15; Protégés, n=15) participated in numerous forms of professional development including: 3-4 workshops, videotaped lesson exchanges, school visit exchanges, and chat room correspondence. A third group of teachers (Control, n =17) received no further training. Based on EPEC fitness activity (e.g., exercise up to 12 minutes) and EPEC activity-related knowledge (e.g., beneficial effects of activity), the questionnaire measures determinants of teachers' intentions as well as their self-reported behaviors. Internal consistency reliabilities for all instruments across all administrations exceeded .80. Validity of the scores from the instruments were established through a variety of methods. All teachers completed pre and post TPB instruments. Since a MANOVA assessment indicated that the three groups were not equal at pretest, ANCOVA was used. Pre-post ANCOVA results showed group differences with the mentors and protégés significantly different from the control group (but not each other) on fitness activity for attitude, control, intention and behavior, as well as a group by time interaction for subjective norm (e.g., control variable F(3, 72) = 37.66, p<.001). Similar trends were found for the activity-related knowledge instruments. RM ANOVA with the pretest as a covariate also identified some differences between mentors and protégés across five instrument administrations over the year. Hierarchical linear regression results suggest that the TPB model was supported with the four variables (i.e., attitude, subjective norm, control, intentions) predicting teachers' behaviors (R2 = .60). The results suggest that extensive curriculum-based professional development programs can lead to increased intentions to teach and more content taught. Keyword(s): physical activity, professional development