Enzyme-linked immunosorbent assays (ELISAs) were used to detect antibodies to the C6 peptide of the Borrelia burgdorferi VlsE protein and a selection of B. burgdorferi IgG antigens, separately and as a combination, in 355 serum specimens from blood donors and patients. Western immunoblotting was used as the reference method. The sensitivity of the combined analysis of IgG antigen and C6 peptide analysis was markedly superior to those of the separate analyses. When the C6 peptide and IgG results were concordant, the customary confirmatory Western immunoblotting assay could be omitted, thus reducing the time and cost of analysis.