Our objective was to assess the prevalence of autoantibodies in patients with leprosy. Forty-one cases of lepromatous leprosy were studied. For the detection of autoantibodies we used the Elisa technique using the following purified antigens in an Elisa assay: dsDNA, ssDNA, histone, mitochondria, RNA, RNP, SS-A, SS-B, Sm, Scl-70, Anca C, Anca P and the cardiolipin complex. As a "cut off" point we used values shown on previous studies to differentiate normal from elevated values. Antibodies to SS-B, mitochondria and cardiolipin were the most prevalent in our study. Antimitochondrial antibodies distinct from those seen in primary biliary cirrhosis and antiphospholipid antibodies with variable ligand activity to B2GIP are frequent in the sera of leprosy patients.