Background: High serum levels of anti-tissue-transglutaminase-2 IgA antibodies (anti-TG2), which are produced and deposited in the intestine, characterize celiac disease. Aim: To assess the diagnostic value of intestinal deposits of anti-TG2 IgA for celiac disease in a paediatric population. Methods: 344 children underwent duodenal biopsy for the suspicion of CD, and were divided into 3 groups: group A, 144 celiac subjects with villous atrophy (Marsh 3b-c); group B, 109 subjects with high serum levels of anti-TG2 but normal intestinal mucosa (Marsh 0-1) (potential celiac disease patients); group C, 91 subjects with normal levels of serum anti-TG2: 70 with Marsh 0-1 and 21 with Marsh 3a mucosa. All duodenal sections were evaluated for the presence of intestinal deposits of anti-TG2 IgA by double immunofluorescence. Results: Deposits of anti-TG2 IgA were present in 96%, 68%, 12% of patients from groups A, B, C, respectively. Diagnostic sensitivity and specificity for celiac disease were 96% and 88% vs. 97% and 100% for serum anti-TG2, respectively. The degree of concordance with serum anti-TG2 was 85%. Conclusion: Detection of intestinal deposits of anti-TG2 IgA is a useful diagnostic tool. Further research is needed regarding their ability to predict evolution to villous atrophy in potential celiac disease. (C) 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.