Mental health comorbidities can negatively affect disease management in adolescents with chronic illnesses. This study sought to determine the prevalence and impact of mental health issues in a population of adolescents and young adults with type 1 diabetes. A cross-sectional study of 150 patients aged 11 to 25 years with type 1 diabetes from an urban, academic diabetes center was conducted. Participants completed 3 validated mental health disorder screening instruments: Beck's Depression Inventory, the Screen for Child Anxiety Related Emotional Disorders-41 anxiety screen, and the Eating Disorder Screen for Primary Care. More than a third screened positive: 11.3% for depression, 21.3% for anxiety, and 20.7% for disordered eating (14.7% had ≥2 positive screens). Patients with a positive screen had twice the odds of having poor glycemic control as those without, as measured by HgbA1c. This study supports screening for mental health issues in adolescents and young adults with type 1 diabetes.