Thirty one patients with antiphospholipid antibodies who developed multi-organ failure ("Catastrophic Antiphospholipid Syndrome") are reviewed. Thirteen suffered from a 'Primary' antiphospholipid syndrome, 13 from defined SLE, 4 from 'lupus-like' disease and one from rheumatoid arthritis. In more than one third precipitating factors were evident (e.g. infections, major/minor surgical procedures, oral contraceptives). Death occurred in 60% of patients from a variety of causes (myocardial failure, ARDS, CNS causes or, often a combination). Disseminated Intravascular Coagulation was present in 8 of 31 patients. Plasmapheresis appeared to be useful in several who had not responded to conventional therapy (e.g. IV heparin, steroids, immunosuppression).