To establish methodological standards for serological investigation and screening of coeliac disease, a joint venture has been launched by the European Medical Research Council and the European Society for Paediatric Gastroenterology and Nutrition. Before general screening can be recommended, robust methods and technical standards ought to be introduced. Joint test protocols were defined: an enzyme-linked immunosorbent assay for IgG and IgA gliadin antibodies and an immunofluorescent test for IgA endomysium antibodies. Protocols have now been tested prospectively by one laboratory. Eighty-eight Tuebingen patients were studied (47 coeliac disease on normal diet, 22 coeliac disease on a gluten-free, and 19 disease controls). Single tests did not produce acceptable levels, but combinations of IgA gliadin antibodies and IgA endomysium antibodies showed 98% sensitivity, 100% specificity and 98% predictive efficiency. Only standardized and refereed methods established by ring testing can serve as a reliable basis for serological coeliac screening.