Fifty patients presenting sequentially with a history of recurrent aphthae were investigated for evidence of nutritional deficiencies and coeliac disease. In the group, two patients were found to have coeliac disease and their recurrent aphthae cleared soon after starting a gluten free diet. This study confirms the presence of an increased prevalence of nutritional deficiency and of coeliac disease in aphthous patients. However, it is recommended that jejunal biopsy be carried out in these cases only where there is evidence of malabsorption.