Celiac sprue is permanent lifelong intolerance of gluten which in some sensitive individuals leads to an inflammation of various grades followed by atrophy of jejunum mucosa. Diagnosis of celiac sprue is based on proof of histopathological changes in jejunum mucosa as a result of presence of gluten in food. In recent years, serum endogenous myosin and tissue transglutaminase antibodies were used in a diagnostic algorithm. We distinguish active, silent, latent, and potential celiac sprue. Simultaneous incidence of type I diabetes mellitus and celiac sprue has been documented in a range of studies. Both diseases have common immunology and genetic characters. Prevalence of celiac sprue in patients with type I diabetes is several times higher compared to prevalence of this disease in the population. There is the prevalence of celiac sprue 3.6-5.1% in children with type I diabetes mellitus in the Czech Republic, silent form of the disease is the most frequent one. An effect of a strict gluten free diet on a metabolic control of diabetes has not been proved. It is necessary to assess (at least once per two years) actively and on regular basis endogenous myosin and/or tissue transglutaminase antibodies in patients with type I diabetes.