Background: This study aimed to determine the prevalence of celiac disease in type I diabetic patients and to compare the symptoms and complications of celiac in patients with diabetes and celiac with patients with diabetes only. Methods: A total of 241 type I diabetic patients age ≥ 18 who needed insulin intake were recruited from diabetic patients attending the Diabetic Research Center in Kermanshah, Iran. Sample was screened for celiac disease by drawing 5cc blood for complete blood count (CBC), and anti-endomysial antibody test (AEA). Patients then were classified based on immunofluorescent method for the presence of AEA. Those with AEA positive underwent biopsy. The biopsy tissues were classified based on Marsh classification. Results: Twenty one patients tested positive for celiac disease based on AEA test (8.7%) and 20 (8.3%) tested positive based on the biopsy. Prevalence of celiac among diabetic patients in comparison to normal population was 8.3% vs. 0.6%; and 70% were in the stages III and IV. Weight loss was significantly more prevalent among the celiac patients, who were 4 times more likely to lose weight. Other parameters such as anemia, mucocutaneous and cutaneous hemorrhage, milk intolerance, related oral aphthous, diarrhea and steatorrhea, alopecia, dermatitis herpetiform and alopecia were higher in celiac patients but not high enough to be statistically significant. Conclusions: There is a need to improve screening identification and treatment of celiac among all diabetic patients type I, especially in cases with uncontrolled diabetic or weight loss.