Lyme disease is a tick-borne illness that is widespread in North America, especially in the northeastern and northcentral United States. This disease could negatively influence efforts to conserve natural populations in two ways: (1) the disease could directly affect wild animal health; and (2) tick control efforts could adversely affect natural populations and communities. Lyme disease affects several domestic animals, but symptoms have been reported in only a few wild species. Direct effects of Lyme disease on wild animal populations have not been reported, but the disease should be considered as a possible cause in cases of unexplained population declines in endemic areas. Methods available to manage ticks and Lyme disease include human self-protection techniques, manipulation of habitats and host species populations, biological control, and pesticide applications. The diversity of available techniques allows selection of approaches to minimize environmental effects by (1) emphasizing personal protection techniques, (2) carefully targeting management efforts to maximize efficiency, and (3) integrating environmentally benign techniques to improve management while avoiding broad-scale environmentally destructive approaches. The environmental effects of Lyme disease depend, to a large extent, on the methods chosen to minimize human exposure to infected ticks. Conservation biologists can help design tick management programs that effectively lower the incidence of human Lyme disease while simultaneously minimizing negative effects on natural populations.