To determine the impact of glargine insulin therapy with different nutritional models on key parameters of diabetes including quality of life, behavior in children and adolescents with type 1 diabetes. Age, duration of diabetes, HbA1c, anthropometric data and episodes of severe hypoglycemia were taken from patients' charts. Diabetes quality of life scale and childhood behavior checklist questionnaires were given to each child at the start and at the end of 6 months. Mean age when starting on glargine insulin was 15.5 ± 3. 8 years. Duration of diabetes was 7.1 ± 4.3 years. About 14 of the patients chose to be in the carbohydrate counting group, whereas 24 of them continued with exchange meal plan as nutritional model. There was a reduction in HbA1c levels from 7.86 to 7.1% in the carbohydrate group and 8.8 to 8.0% in the exchange meal plan group. Total daily insulin dose did not change in both of the groups. BMI did not change in both of the groups. Diabetes-related worries decreased in carbohydrate group. No change was found in the behavior scores in both of the groups at the end of the study period. The use of glargine therapy among adolescents with type 1 diabetes was associated with improved overall glycemic control. © 2007 Springer-Verlag.