Hemolytic-uremic syndrome (HUS) is a rare disease but may be fatal in the absence of appropriate treatment. It is the first cause of acute renal failure (ARF) in children and is less frequently observed in adults. We report the case of a 50 years old woman who was first admitted in the surgery department for intestinal occlusion. Haematological and renal disorders were not recognised initially. Specific treatment with plasma exchanges was beneficial. This case was idiopathic but in 50% of HUS in adults, an aetiology can be found and sometimes treated: drugs, pregnancy, systemic diseases, hypertension or cancer. Although still debated, treatment is based on fresh frozen plasma infusion, associated or not to plasma exchanges. Some other therapies can be added: steroids, polyvalent immunoglobulin infusion, vincristin or splenectomy. In all cases, blood pressure control must be obtained, especially with ACE inhibitors. Response to treatment is often excellent, but chronic renal failure persists in about 25% of cases in adults. Recurrences are rare and occur mainly in patients with an hereditary factor H deficiency. The hemolytic-uremic syndrome should be diagnosed and treated immediately.