Knowledge of the host-feeding behavior and extent of interactions with human hosts are important in evaluating the role and vector potential of invasive mosquitoes in transmission of native arboviruses. We collected blood-engorged females of the recently established exotic species Aedes japonicus japonicus from sites in New Jersey during 2000 to 2007 and identified the sources of vertebrate blood meals by sequencing portions of the cytochrome b gene of mitochondrial DNA. Over 1/3 (36%, n = 36) of the engorged mosquitoes acquired blood meals from humans. Other mammalian hosts included white-tailed deer (53%), fallow deer (5%), horse (3%), and Virginia opossum (3%). No avian, amphibian, reptilian, or mixed blood meals were identified. Our detection of a comparatively high prevalence of human bloodfeeding in Ae. j. japonicus in association with its local abundance, vector competence, and repeated detection of West Nile virus from field-collected specimens illustrates the potential for this invasive mosquito to serve as a "bridge" vector in transmission of West Nile and other mosquito-borne viruses in North America.