A pro-thrombotic condition was described in 1983 which was characterised by the presence of circulating antiphospholipid antibodies, as well as peripheral thrombosis (e.g. DVT), a tendency to internal organ involvement, repeated miscarriage, and, occasionally, thrombocytopenia (aPL) (Hughes, Br Med J 287:1088-1089, 1983). Previously, there had been a number of observations, mainly in patients with lupus having "false positive" tests for syphilis, miscarriage and circulating lupus anticoagulants. The description in 1983 had three notable features (a) a detailed comprehensive clinical picture of the syndrome; (b) this description differed from other coagulopathies in showing a propensity for arterial thrombosis (e.g. stroke and heart attack); and (c) this was a syndrome quite independent from lupus. There are indications that the primary antiphospholipid syndrome will turn out to be more common than lupus, though this could still be a reflection of referral practice.