BackgroundThe progress of technology in developed countries has changed lifestyles to sedentary and has increased non-communicable diseases. Identifying factors affecting patterns of physical activity among adolescents is valuable and it is important to change these pattern.ObjectiveThis study aimed to explore teenage girls’ experiences regarding the determinants of physical activity promotion based on Pender’s Health Promotion Model.MethodsThis qualitative study is a content analysis research on the girls of three high schools in Minoodasht city for six months from September 2015 until the end of February 2016. The data were obtained by focused group discussions and semi-structured in-depth interviews from 48 girls ranging from 15 to 18 years old and six teachers. Data analysis was done using theory-driven qualitative content analysis.ResultsData analysis resulted in a total number of 53 primary codes which were classified in the six predetermined classifications of Pender’s Health Promotion Model (Perceived benefits, perceived barriers, perceived self-efficacy of physical activity behavior, feelings related to physical activity behavior, interpersonal and situational influencers). The results showed that two classifications (perceived barriers, and situational influencers) were considered more important than other classifications in reducing levels of physical activity in adolescent girls and also high self-efficacy for promoting physical activity in adolescents.ConclusionThe results obtained from this study specified the determinants affecting the promotion of physical activity among adolescent girls and can help the planners to choose the most appropriate methods and strategies in order to promote physical activity among adolescent girls and to prevent chronic non-communicable diseases in this age group and gender.