During the summers of 1982 and 1983, black-tailed prairie dogs (Cynomys ludovicianus) were examined for parasites. Those collected and their respective prevalence included Linognathoides cynomyis (46.3%), Opisocrostis hirsutus (53.7%), Opisocrostis tuberculatus cynomuris (2.4%), Androlaelaps fahrenholzi (12.2%), Ixodes sculptus (2.4%) and Dermacentor andersoni (4.9%). The collection data indicated that L. cynomyis, O. hirsutus and A. fahrenholzi were at low population densities during this period.