Coeliac disease, also called permanent gluten sensitive enteropathy, has recently been recognised as constituting a widespread health problem. Effective treatment involves the strict exclusion of wheat, rye, barley and possibly also oats from the diet. Genetic susceptibility and the presence of gluten in the diet are prerequisites for developing the disease. Sweden has recently experienced an epidemic of coeliac disease in children below 2 years of age. Previously, considerable changes in incidence over time have also been reported from England, Scotland and Ireland. Such obvious changes in incidence over rather short time periods, in genetically stable populations, emphasise the importance of environmental factors in the aetiology. Thus, most likely, the aetiology of coeliac disease is multifactorial. However, further conclusive evidence is required to settle if environmental factors, beyond presence of gluten in the diet, really influence the immunological process resulting in the coeliac small intestinal lesion, or merely influence the clinical expression of the disease. The search for contributing exposures has thus far focused on early feeding, suggesting that breast-feeding duration and the amount of gluten consumed are of importance, and possibly also the age for introducing gluten into the diet of infants. The pattern of causation may vary over time and between countries, however, which may obscure the search for risk factors. Nevertheless, a challenging possibility that needs to be explored is if coeliac disease can be delayed, or possibly even prevented for an entire life span, by favourable dietary habits.