Since the 1990's, the widespread use of very sensitive and specific serological tests has completely changed the conditions of the diagnosis of celiac disease (CD). The active form of the disease is now only the tip of the iceberg representing it. Currently, CD is evoked either in front of mild digestive symptoms at the usual age or in the course of screening in siblings of an index case or in patients at risk (insulin dependent diabetes for example) at a later age using IgA anti-endomysium or anti-tissue transglutaminase antibodies, the sensitivities and specificities of which exceed 90%. In some cases, HLA typing is helpful in allowing to exclude a patient who is neither DQ2 nor DQ8. The intestinal biopsy remains the "gold standard" of the diagnosis showing villous atrophy; the latter, however, is less and less often severe as the disease is milder and milder. The diagnosis of CD then rests on the confrontation of the clinical, biological and histological data. Once CD has been diagnosed, it can be classified either as active or silent (positive serology with isolated villous atrophy), or latent (positive serology with a normal mucosa) and the appropriate therapeutic decision can be taken.