Long standing coeliac disease is associated with an increased risk of malignancy, not only of intestinal lymphoma but also small intestinal adenocarcinoma. Two patients whose initial presentation was adenocarcinoma of the small bowel, but who were subsequently found to have coeliac disease after Whipple's resection, are described. The diagnosis was made early in the postoperative period in the first patient after close histological examination of the tumour-free mucosal margins. This patient was placed on a gluten-free diet and had an uncomplicated postoperative recovery with rapid weight gain. Diagnosis and dietary intervention in the second patient was very delayed and resulted in the development of severe malabsorption and weight loss. This illustrates the importance of ruling out coeliac disease prior to surgery in patients with small intestinal malignancies.