The term 'catastrophic' antiphospholipid syndrome (APS) is used to define an accelerated form of APS resulting in multiorgan failure. Although catastrophic APS patients represent less than 1% of all patients with APS, they are usually in a life-threatening medical situation that requires high clinical awareness. The careful and open discussion of several proposals by all participants in the presymposium workshop on APS consensus, held in Taormina on occasion of the 10th International Congress on aPL and chaired by Munther A Khamashta and Yehuda Shoenfeld (29 September 2002), has allowed the acceptation of a preliminary set of classification criteria. On the other hand, the optimal management of catastrophic APS must have three clear aims: to treat any precipitating factors (prompt use of antibiotics if infection is suspected, amputation for any necrotic organ, high awareness in patients with APS who undergo an operation or an invasive procedure), to prevent and to treat the ongoing thrombotic events and to suppress the excessive cytokine 'storm'. Anticoagulation (usually intravenous heparin followed by oral anticoagulants), corticosteroids, plasma exchange, intravenous gammaglobulins and, if associated with lupus flare, cyclophosphamide, are the most commonly used treatments for catastrophic APS patients.