This study investigated the susceptibility of nilgai antelope to Babesia bovis infection, transmitted by Rhipicephalus (Boophilus) spp. Despite R. (B.) microplus infestation in South Texas, the role of nilgai in parasite transmission remains unclear. Nilgai were inoculated with B. bovis merozoites or sporozoites, alongside Bos taurus beef calves as controls. Monitoring included daily temperature and hematocrit checks, blood collection for PCR and ELISA diagnostics, and histological examination of cerebral tissue for infection evidence. Bovine calves were then sub-inoculated with blood from challenged nilgai and monitored for infection signs. Additionally, in vitro cultures examined parasite colonization of red blood cells from both nilgai and cattle.