OBJECTIVE: The objective of the study was to report on the measurement properties of the revised and updated Pediatric Quality of Life Inventory (PedsQL) 3.2 Diabetes Module for children, adolescents, and young adults with type 1 diabetes. RESEARCH DESIGN AND METHODS: The 33-item PedsQL 3.2 Diabetes Module and PedsQL Generic Core Scales were completed in a 10-site national field test study by 656 families of patients ages 2-25 years with type 1 diabetes. RESULTS: The 15-item Diabetes Symptoms Summary Score and 18-item Diabetes Management Summary Score were derived from the factor analysis of the items. The Diabetes Symptoms and Diabetes Management Summary Scores evidenced excellent reliability (patient self-report alpha = 0.88-0.90; parent proxy report alpha = 0.89-0.90). The Diabetes Symptoms and Diabetes Management Summary Scores demonstrated construct validity through medium to large effect size correlations with the Generic Core Scales Total Scale Score (r = 0.43-0.67, P < 0.001). HbA1c was significantly correlated with the Diabetes Symptoms and Diabetes Management Summary Scores (r = -0.21 to -0.29, P < 0.001). Minimal clinically important difference scores ranged from 5.05 to 5.55. CONCLUSIONS: The PedsQL 3.2 Diabetes Module Diabetes Symptoms and Diabetes Management Summary Scores demonstrated excellent measurement properties and may be useful as standardized patient-reported outcomes of diabetes symptoms and diabetes management in clinical research, clinical trials, and practice in children, adolescents, and young adults with type 1 diabetes.