A goal of Healthy People 2010 is to get 30% of American adults involved in muscular fitness-promoting behaviors on a regular basis. Overall, only 8.7% of American adults do so, with the highest level of involvement (15.1%) observed for those between 17-29 yr. (Galuska et al., 2002). In France the situation is similar, with approximately 10% of those between 15-75 yr. engaging in such behaviors (Ministre de la Jeunesse et des Sport, 2001). Theoretically based research is needed to identify potential correlates of muscular fitness promoting behaviors. Also, given an increasingly pluralistic world view and the paucity of cross-cultural studies in the sub-discipline of Sport and Exercise Psychology, a need for such research has been identified (Ram et al., 2004). The purpose of this study was to examine American and French college students’ stage of change for muscular fitness promoting behaviors and to identify potential behavioral, biometric, psychological (i.e., cons, pros, self-efficacy; derived mainly the Transtheoretical Model [TTM]), and sociocultural correlates. Participants were American (n = 231) and French (n = 171) college students majoring in exercise and sport science (M age = 20.3 yr., M BMI = 23.4 kg/m2), most of whom were male (55%), Caucasian (83.8%), and underclassman (73.4%). Participants completed all measures in their native language using the translation process outlined by Banville et al. (2000). Resulting Cronbach alpha reliability coefficients ranged from .60 to .80. The majority of Americans reported being in the action and maintenance stages of change, whereas the majority of French reported being in the precontemplation or contemplation stages of change (66.2% and 56.8%, respectively, p <.001). Using 21 predictor variables, and proportional to group size, participants in all stages could be distinguished from one-another (p <.001), except for those in preparation and contemplation (p = .49). The overall stage of change classification accuracy was 58.2% (Wilks’ l = .29, p = .001). The most reliably classified stages were preparation (57%), precontemplation (72.5%), and maintenance (80%). The most important predictor variables, in order of entry, were: current involvement in muscular fitness, nationality, pros, number of exercises performed per day, self-efficacy, and the number of months of involvement. These results will be discussed within the context of the psychosocial and sociocultural differences observed, and the internal and external validity of TTM. Funded by a Ruth E. Warnke Senior Scholar Award and a URISC grant.Keyword(s): health promotion, international issues, physical activity