Serum samples were collected from white-footed mice (Peromyscus leucopus) and raccoons (Procyon lotor) during 1983, 1984, and 1990 through 1993 in Connecticut (USA) and were tested in enzyme-linked immunosorbent assays (ELISA) against whole cell Borrelia burgdorferi sensu stricto (strain 2591) and the following recombinant antigens of this spirochete: p41-G (an immunogenic epitope of flagellin), outer surface protein (OSP)A, and OSPB. Antibodies were most frequently detected when whole cell antigen was used in the analyses. Reactivity to highly specific recombinant antigens also occurred and was particularly helpful in verifying B. burgdorferi infection. Geometric mean antibody titers for assays with whole cell antigen ranged from 453 to 2,363 and were at least two-fold higher than geometric means calculated for tests with recombinant antigens, which ranged from 226 to 640. With greater sensitivity, an ELISA with whole cell antigen is preferred for determining presence of antibody in sites enzootic for Lyme borreliosis. However, use of highly specific recombinant antigens, particularly OSPA and OSPB, in an ELISA can provide supportive information in ecological studies of this disease.