This study examined the relationship between illness uncertainty, perceived control, and psychological distress among adolescents with type 1 diabetes. Sixty-eight adolescents age 13 to 18 years with type 1 diabetes completed the Children's Uncertainty in Illness Scale, the Perceived Control Scale Media Relations, and the Brief Symptom Inventory. Increased uncertainty was significantly associated with both decreased perceived control and increased psychological distress. Further analyses indicated that the relationship between illness uncertainty and psychological distress was direct and was not mediated or moderated by perceived control. These findings suggest that interventions aimed at managing uncertainty may help decrease psychological distress among adolescents with diabetes.