Objectives: By using pediatric diabetes quality registries in Austria, Germany, and Sweden treatment of type 1 diabetes and the outcome of care during the vulnerable adolescence period were compared. Methods: Data in DPV, broadly used in Austria and Germany, and Swediabkids used in Sweden, from clinical visits in the year 2013 on 14 383 patients aged 11 to 16 years regarding hemoglobin A1c (HbA1c), insulin regimen, body mass index (BMI)-SD score (SDS), blood pressure, hypoglycemia, ketoacidosis, and smoking habits were analyzed. Results: Patients in Sweden had fewer clinical visits per year (P amp;lt; .05), lower insulin dose per kg (P amp;lt; .001), and lower proportion of fast acting insulin compared with Germany and Austria (P amp;lt; .001). The proportion of pump users was higher in Sweden (P amp;lt; .001). Patients in Sweden had lower mean HbA1c levels (Austria: 64 mmol/mol, Germany: 63 mmol/mol, and Sweden: 61 mmol/mol [8.0%, 7.9%, and 7.7%, respectively]; P amp;lt; .001). The frequency of severe hypoglycemia was higher in Sweden while it was lower for ketoacidosis (3.3% and 1.1%, respectively) than in Austria (1.1% and 5.3%) and Germany (2.0% and 4.4%) (P amp;lt; .001). Girls in all 3 countries had higher HbA1c and BMI-SDS than boys. Conclusions: Sharing data between diabetes registries and nations enables us to better understand differences in diabetes outcome between countries. In this particular comparison, pediatric patients with diabetes in Sweden were more often treated with insulin pump, had lower HbA1c levels and a higher rate of severe hypoglycemia. Patients in Austria and Germany used rapid acting insulin analogs more often and had a lower rate of ketoacidosis.