BACKGROUND: Significant proportions of young people experience body dissatisfaction, which has implications for psychological and physical well-being. Lesson content and perceived competence may be important variables for the experience of body dissatisfaction, yet these have been underexplored in physical education. The aim of this cross-sectional study is to identify the relationships between body dissatisfaction and perceptions of competence, and to explore whether body dissatisfaction depends on lesson content. METHODS: A paper-and-pencil questionnaire was completed by 446 (210 boys, 236 girls) 13- to 14-year-old pupils from 37 physical education classes. The questionnaire assessed body dissatisfaction and perceived competence in physical education. Lesson content was also recorded. Twenty-nine of the classes were engaged in team activities, eg, ball games. Eight classes were engaged in individual activities, eg, fitness. RESULTS: Multilevel analysis identified a significant negative association between body dissatisfaction and perceptions of competence in physical education. Lesson content did not significantly predict variations in body dissatisfaction scores. CONCLUSIONS: Teachers should focus on enhancing pupils' perceptions of competence in physical education to support the development of body satisfaction.