Summary Moderately raised levels of circulating anticardiolipin antibodies were found in 14 of 30 patients witb active Adamantiades-Bebget's disease (46.7%) wbo were not receiving treatment. Three patients sbowed the IgG isotype, nine the IgM isotype, and two bad botb IgG and IgM isotypes. Statistical analysis, to determine possible correlations between anticardiolipin antibodies and clinical features, and meta-analysis of the data available, were performed. A positive correlation between erytbema nodosum and bistologically confirmed cutaneous vasculitis and the presence of circulating anticardiolipin antibodies of tbe IgM isotype was found (P=0.017 and 0.018, respectively). wbereas the IgG isotype did not correlate with any clinical feature. Evaluation of data on other clinical manifestations showed no correlation, either with the IgG or IgM isotypes. In particular, there was no association of circulating anticardiolipin antibodies with tbe incidence of thrombosis, systemic vasculitis, retinal involvement or neurological features. These results suggest that anticardiolipin antibodies do not play a major patbogenetic role in Adamantiades-Bebget's disease, but they may serve as an additional marker for a risk of the development of cutaneous vasculitis such as erythema nodosum.