To investigate the influence of celiac disease (CD) on growth and metabolic control in a nationwide cohort of children and adolescents with type 1 diabetes (T1D). We analyzed data from 19, 796 pediatric patients with T1D in the German pediatric multicenter DPV-database for occurrence of CD. CD-specific antibodies were present in 1326 patients (6. 7% ). The diagnosis was confirmed in 127 patients (0. 6% ) by small-bowel biopsy. Female subjects were significantly more predisposed to have T1D and CD. The CD-affected patients in our cohort were significantly younger at diabetes onset. Furthermore, they had significantly lower height-SDS at onset (-0. 49 vs-0. 06, P < .05), a difference that increased during the course of the disease (-0. 80 vs-0. 26 after 9 years of diabetes, P < . 05). In addition, body mass index-SDS significantly differed between the groups (0. 22 vs 0. 47, P < . 05). Evidence for thyroid disease was more commonly observed in the T1D with CD group (6. 3% vs 2. 3% , P < . 05). HbA1c values were lower in the patients with T1D and CD. The CD-positive patients were characterized by earlier onset of diabetes and decreased growth and weight gain. These findings emphasize the clinical relevance of celiac disease in patients with autoimmune diabetes. To investigate the influence of celiac disease (CD) on growth and metabolic control in a nationwide cohort of children and adolescents with type 1 diabetes (T1D). We analyzed data from 19, 796 pediatric patients with T1D in the German pediatric multicenter DPV-database The diagnosis was confirmed in 127 patients (0.6%) by small-bowel biopsy. Female subjects were significantly more predisposed to have T1D and CD. The CD-affected patients in our cohort were significantly younger at diabetes onset. Furthermore, they had significantly lower height-SDS at onset (-0. 49 vs -0.06, P <.05), a difference that increased during the course of the disease (-0.80 vs-0. 26 after 9 years of diabetes, P <.05). In addition, body mass index-SDS significantly differed between the groups (0.22 vs. 0.47, P <. 05). Evidence for thyroid disease was more commonly seen in the T1D with CD group (6.3% vs 2.3%, P < . 05). HbA1c values ​​were lower in the patients with T1D and CD. The CD-positive patients were characterized earlier earlier of diabetes and decreased growth and weight gain. These findings emphasize the clinical relevance of celiac disease in patients with autoimmune diabetes.