One hundred and seventy-three consecutive patients with rheumatoid arthritis were examined for the presence of anticardiolipin antibodies (ACA), and for the clinical relevance and the relation of these antibodies to skin manifestations. Abnormally elevated IgG- and/or IgM-ACA levels were detected by an enzyme-linked immunosorbent assay in the sera of 55 (32%) patients. There was no statistical evidence of an association between ACA and a history of thrombosis in these patients. However, ACA were statistically significantly linked to the presence of rheumatoid nodules, which were found in 36 (21%) patients. In three patients, ACA were associated with vascular manifestations, including livedo reticularis, thrombophlebitis, and leucocytoclastic vasculitis. Our findings suggest that, although a subset of ACA may be linked to cutaneous vascular conditions, the major fraction of ACA in rheumatoid arthritis may have a different specificity than in other diseases, in which ACA are often linked to thrombotic events.