Adult Still's disease (ASD) is a rare systemic disorder characterized by fever, arthralgia, cutaneous rash, and lymphadenopathy, with high polymorphonuclear leucocytosis and low glycosylated ferritinaemia. Kidney involvement has been reported rarely. We present a patient with ASD who developed haemolytic uraemic syndrome (HUS). The 42-year-old patient was admitted for unexplained fever related to ASD according to Yamaguchi's classification criteria. As Still's disease was resistant to prednisone, high-dose intravenous immunoglobulins (IV Ig) were administered. During the follow-up the patient developed acute renal failure and non-immune haemolytic anaemia with high levels of antiphospholipid antibodies (IgG anticardiolipin antibodies and anti-beta2 glycoprotein 1 antibodies). Renal biopsy disclosed thrombotic microangiopathy (TMA) with arteriolar and glomerular involvement. Treatment with steroids and intravenous IV Ig was reinitiated but renal function worsened towards end-stage renal failure. In this case, we suggest that antiphospholipid antibodies could have promoted arteriolar and glomerular TMA. HUS may be the cause of acute renal failure in Still's disease.