Thrombotic angiopathies, i.e. haemolytic uremic syndrome and thrombotic thrombocytopenic purpura, are thought to occur in patients with a combination of risk factors (e.g., an infection with shiga-toxin-producing Escherichia coli (E. coli) or low activity of the metalloproteinase Adamts-13) and a pathophysiological trigger (e.g., anti-endothelial antibodies, cytokines or activation of chemokine receptor 4). To our knowledge, this is the first report describing an association between haemolytic uremic syndrome and routine surgery and anaesthesia. We present a case in which a 67-year-old Caucasian female developed fatal haemolytic uremic syndrome in the immediate postoperative period of uncomplicated day care surgery. The patient had suffered gastrointestinal symptoms followed by confusion approximately two weeks before surgery, but had been without any symptoms in the week before surgery. Haemolytic uremic syndrome with cerebral symptoms ranging from initial anxiety to subsequent seizures and coma developed within a few hours after the end of surgery. In addition, acute kidney failure and severe thrombocytopenia occurred about the same time. During intensive care, the patient was found to be positive for enterohaemorrhagic E. coli (EHEC) in faeces. Anaesthesiologists should be notified that haemolytic uremic syndrome is an uncommon differential diagnosis in patients with postoperative seizures and coma. Patients with a recent enterohemmoragic E.Coli infection should be followed postoperatively for signs of haemolytic uremic syndrome.