The dynamics of a natural focus of L. pomona in skunks and opossums were investigated by live trapping for a period of 18 months, followed by removal trapping for 2 months. Leptospira pomona was isolated from 8 (10.6%) of 75 skunks, 3 (3.1%) of 98 opossums and 1 of 21 feral cats. Serologic reactions to L. pomona were found in 9 (28.1%) of 32 skunks and 3 (3.01%) of 98 opossums tested. Leptospira pomona was isolated from 1 to 3 times from naturally infected free-living skunks during a maximum of 77 days. Among the interesting correlations of ecologic data with infectivity was a significant relationship between both isolations and serologic titers for the colder and wetter parts of the year in skunks; no such correlation was found for opossum infections and titers. The habits of animals shedding leptospires were found to be related to specific parts of the research area. The authors conclude from the data that skunks may be able to maintain a nidus of L. pomona.