The radiographs in 10 surgically proven cases of caecal volvulus have been analysed. In the majority of cases of caecal volvulus a plain film diagnosis is suggested by the observation of the haustrated and disproportionately dilated viscus located anywhere in the abdomen. There is often evidence of small intestinal air--fluid distension. Identification of an air-filled appendix attached to the disproportionately dilated viscus provides conclusive plain film evidence of the condition. Difficulties in the diagnosis may be encountered where the caecum is fluid filled and when proximal small intestinal distension obscures the dilated caecum. Barium enema examination provides a definitive pre-operative diagnosis.