Several epidemiological studies show that celiac disease with extraintestinal manifestations is 15 times more frequent than celiac disease with intestinal symptoms. Fifteen years ago the iceberg model was proposed to explain the epidemiology of this disease. On the one hand, there are a quantifiable number of patients who are correctly diagnosed since they have symptoms suggestive of this disease and who form the visible part of the iceberg. However, several studies using screening serology demonstrate that for each patient diagnosed, there is a mean of 5-10 patients without a diagnosis. These patients form the submerged part of the iceberg (monosymptomatic or silent celiac disease). The most widely accepted strategy to investigate the submerged part of the "celiac iceberg" is screening of known risk groups through a systematic search for celiac disease in these groups.