Human babesiosis is a malaria-like illness caused by protozoan parasites belonging to the genus Babesia. In the United States, the most commonly identified pathogen for human infections is Babesia microti which is transmitted principally by the blacklegged tick, Ixodes scapularis. This article reviews epidemiological aspects of the disease with focus on its tick vector and transmission risk. Clinical presentations, diagnosis, and treatment of the disease are also briefly discussed.