Non occlusive mesenteric ischaemia is a serious complication of maintenance haemodialysis. Its physiopathological mechanisms are controversial and its frequency is underestimated. Eight cases (in 5 patients) are reported: the clinical syndrome consisted of acute abdominal pain without evidence of shock or abdominal wall rigidity at palpation, associated with hyperleucocytosis and hyperkaliemic acidosis. The normality of the mesenteric vessels was confirmed at autopsy in one patient and during surgery in all others. Two patients were found to have caecal necrosis, 2 had diffuse necrotizing enterocolitis and 1 had necrosis of the left colon. The prognosis of this complication is sombre: 4 of our 5 patients died, including 3 who had relapsed 1, 4 and 18 months respectively after surgery (diffuse ileocolic necrosis). The usually accepted physiopathological mechanism is volaemic contraction consecutive to haemodialysis in often atheromatous subjects; however, the fact that the mesenteric infarction is not occlusive, that it occurs sometime after the end of the haemodialysis session and above all, the lack of haemodynamic changes during or immediately after the session suggest that other factors (bioincompatibility) are involved.