The incidence of anticardiolipin (ACL) antibodies in connective tissue disorders other than systemic lupus was investigated in 113 subjects: 68 had rheumatoid arthritis, 23 primary Sjogren syndrome and 22 had systemic sclerosis. VDRL, thromboplastin time and determination of IgG and IgM ACL antibodies (ELISA) were performed in all subjects. Overall, 45% of patients were positive for ACL antibodies, mostly of the IgG variety (90%). No differences were observed among the investigated diseases. Positive ACL antibodies were not related to evidence of antiphospholipid syndrome nor to clinical characteristics of the different diseases. These results confirm that ACL antibodies may be present in connective tissue disorders other than systemic lupus, but they do not predict the development of antiphospholipid syndrome nor help to characterize the severity of the disease.