In 46 adult patients with coeliac disease, 41 (89%) of whom were positive for IgA and/or IgG antigliadin antibodies (AGA) when untreated, we investigated after a gluten-free diet the relationship between the persistence of AGA, the persistence of jejunal lesions, and the duration and compliance with the diet. IgG AGA were positive in 21 coeliac patients (46%) after variable periods of gluten-free diet and were associated with IgA positivity only in 4 cases (9%). Both IgA and IgG AGA positivity appeared to be more related to the lack of improvement of the jejunal lesions than to the strictness and duration of gluten withdrawal. Nine coeliacs showed no improvement of jejunal lesions after the gluten-free diet. Of these 9, 4 showed persistent IgA AGA, while the remaining 5 resulted IgAAGA-negative as before when untreated. Though intestinal biopsy remains the best means of determining the positive effect of gluten withdrawal, the persistence of IgA AGA in treated coeliacs is always predictive of the persistence of severe jejunal lesions. The persistence of IgG AGA, on the contrary, should be regarded as an immunological memory.