We aimed to evaluate the effects of a gluten-free diet on growth and glycemic control in children with type 1 diabetes mellitus (DM) and asymptomatic, biopsy-proven celiac disease (CD). Each case of CD was compared to two children with DM and no CD. We studied weight, height, and hemoglobin A1c (HgbAlc) up to 12 months pre- and post- CD diagnosis in 29 cases and 58 controls. The change in body mass index (deltaBMI Z-score) over 2 years was significantly higher in CD cases vs. controls (mean +/- SD 0.33 +/- 0.74 vs. +/- 0.08 +/- 0.46; p = 0.023). However, BMI Z-score did not change in CD patients diagnosed with DM for > 1 year. Mean HgbA1c was similar between groups throughout the study. In conclusion, children with asymptomatic CD and DM do not have significant changes in BMI, height Z-score or metabolic control 1 year post-diagnosis.