The purpose of this study was to examine the relationship between keeping a daily leisure-time physical activity record and adolescent (a) feelings of competence toward leisure-time physical activity, (b) motivational profiles toward leisure-time physical activity, and (c) leisure-time physical activity behaviors. Participants were 124 junior high and high school physical education (PE) students. Students completed the Behavioural Regulation in Exercise Questionnaire–2, the Godin Leisure–Time Exercise Questionnaire, the Perceived Competence Scale, and were assigned to keep an online leisure-time physical activity record for three weeks as part of their regular PE class. A 2 (gender) x 4 (trials) repeated measures ANCOVA was used to examine the relationships between recording compliance and the variables of perceived competence, motivation, and physical activity. Results showed a significant interaction between recording compliance and leisure-time physical activity. As students kept the leisure-time physical activity record, boys' leisure-time physical activity levels significantly increased and girls' leisure-time physical activity levels significantly decreased. Also, a significant interaction between recording compliance and introjected regulation was found. The more students recorded the less motivated they were by guilt and obligation to exercise in their leisure time. Lastly a significant interaction was found between recording compliance and intrinsic regulation, showing that the more students recorded the more intrinsically motivated they were to exercise in their leisure time. Implications and suggestions are set forth for PE professionals.