A total of 278 bats belonging to 16 species was examined for ticks from various sites in New Mexico from 1994 to 1998. Seven species of bats were parasitized by ticks: larvae of Ornithodoros kelleyi Cooley & Kohls, Ornithodoros rossi Kohls, Sonenshine & Clifford (Argasidae), or both. Both species of ticks are reported from New Mexico for the first time. Infestation prevalences for parasitized bats ranged from 2 to 25% on different host species for O. kelleyi and from 7 to 25% for O. rossi. The pallid bat, Antrozous pallidus, and the big brown bat, Eptesicus fuscus, were parasitized by both tick species. No distinct host specificity was noted for either tick species.