The measurement of immunoglobulin A (IgA) endomysial antibodies is now established as an important diagnostic test in gluten-sensitive disease. Monkey oesophagus is the commonly used tissue substrate, but it has been proposed that human umbilical cord tissue may be a suitable alternative for antibody detection. In this study, we report a modified method of examining endomysial antibody reactivity with cord tissue. This involves examination of antibody reactivity with cells in Wharton's jelly, and with umbilical cord blood vessel. A total of 370 patients being investigated for coeliac disease were studied and this diagnosis was established in 42. Endomysial antibodies were found in all 42 using umbilical cord tissue, and the test results were confirmed with monkey oesophagus substrate. In three of the remaining 328 non-coeliacs, a false-positive endomysial antibody test was noted and small intestine histology was normal in these patients. All positive sera were found to react with cells in Wharton's jelly, and reticular staining of blood vessels was also present. Examination for immunofluorescence in both Wharton's jelly and blood vessel components of cord tissue greatly simplified test interpretation.