Intolerance of gluten, resposible for Coeliac disease, is essentially shown by an auto-immune enteropathy, even if the cutaneous manifestation (herpetiform dermatitis) and perhaps certain neurological signs (cerebral syndrome, peripheral neuropathy) may be independent as well as associated with the intestinal illness. This affection is of immunological nature, occuring in a genetic field that predisposes to the illness (familial form: concordance of 70% in homozygote twins; 90% of patients show an HLA molecule of type DQ2, DQ8 in almost all the other cases. The exogenous factor is the gluten content contained in wheat, rye and barley, more precisely by the intermediary "the prolamines" which are the "reactive" element that induces a the same time an inflammatory reaction of type TH11 locally (expressed by the histological aspect of a duodenal biopsy evolving as villous atrophy) and a humoral response with production of anti-gliadine and anti-transglutaminase antibodies (the role of the latter enzyme is intervention in the local transformation of antigens to make them antigenic). It is an illness of adults as well as children and this point must now be emphasized. Recent epidemiological studies insist on a high prevalence (1/300 in Europe). Clinical expression, at the start very polymorphic and so misleading, before the appearance of the more classical signs of malabsorption and development, always feared, towards a lymphoma. These signs are haematological (anemia of various types, hyper platelets by hyposplenism, haemorrhagic signs) cutaneous (herpetiform dermatitis, cutaneous vasculitis) mucosal (aphtose), hepatic (cytolysis), neurophysical (fatigue, troubles of behaviour, cerebral syndrome, neuropathy) and osteo-articulitis (osteopenia, arthralgias, diffuse pains). The association of certain auto-immune illnesses must be emphasized (diabetes, Hashimoto thyroiditis, Gougerot disease, primitive biliary cirrhosis). To think early of the possibility of intolerance to gluten, is to give the means of a very easy diagnosis (measurement of anti-gliadin, anti-endomysium and anti-transglutaminase, and secondarily duodenal biopsy if necessary), and it is early elimination of gluten food which will make the various clinical manifestations disappear and so prevent the risk of evolution to a tumoral pathology.