A retrospective analysis of 125 consecutive lupus anticoagulant (LA) positive patients and 125 age, sex matched lupus anticoagulant negative controls is reported with the aims of defining further the clinical spectrum of disease, determining at-risk subgroups and management strategies. There was no significant difference in the incidence or pattern of complications in those with systemic lupus erythematosus (SLE) and related disorders, and those without SLE. Venous thromboembolism, immune thrombocytopenia, foetal loss, depression and hypertension were statistically more common in the LA group than in the control group. In contrast to previous reports, children aged ten years or less with the LA developed significantly more complications than controls. Patients with the LA secondary to drugs also developed complications, a finding which is also at variance with previous reports. There was a significant difference in the outcome of arterial disease (p < 0.04) and venous thromboembolism (p < 0.001) when long term anticoagulation was part of the treatment regimen.