OBJECTIVE: To document the existence and prevalence of adolescent-generated diabetes management techniques. RESEARCH DESIGN AND METHODS: One hundred forty-four adolescents completed the confidential questionnaire developed for this study. Glycohemo-globin was also obtained for each individual. RESULTS: Within the 10 days before their clinic visit, many adolescents admitted to engaging in various mismanagement behaviors, with 25% admitting to missing shots. Parents tend to underestimate adolescent mismanagement. Missing shots was significantly related to poor control (P < 0.01). Older adolescents engaged in more mismanagement than their younger cohorts (P < 0.001). The questionnaire factored into two subscales: blatant mismanagement and faking. CONCLUSIONS: This study shows the importance of recognizing the prevalence of mismanagement among adolescents.