Berberis thunbergii (Japanese barberry) is an invasive shrub that escaped cultivation and spread in the northeastern United States. The impact of varying degrees of Japanese barberry invasion on the abundances of a Lyme disease bacterium vector, Ixodes scapularis (blacklegged tick), and reservoir, Peromyscus leucopus (white-footed mouse) was investigated. Blacklegged ticks and white-footed mice in three habitats with different levels of Japanese barberry invasion (fully invaded, partially invaded, non-invaded) were surveyed. The efficacy of three tick collection techniques (flagging, dry ice traps, walking) within these habitats were evaluated. Blacklegged ticks and white-footed mice were more abundant in the fully invaded habitat than the non-invaded and partially invaded habitats. The walking method was most effective for collecting blacklegged ticks. Habitat management that prevents full invasion by Japanese barberry may limit the abundance of Lyme disease bacterium vectors and reservoirs, thus contributing to disease management.