Background: In children, haemolytic uraemic syndrome (HUS) is associated with high plasma plasminogen activator inhibitor type 1 (PAI-1), which may contribute to the persistence of renal glomerular and arteriolar thrombi. HUS has been described in HIV-infected patients, but the pathophysiology of HUS in these patients is poorly understood. The aim of the study was to investigate plasma fibrinolytic activity in 18 patients with HIV-associated HUS.