A new nematode species, Subulura mackoi n. sp., is described based on specimens from the colon and caecum of the Eurasian Scops Owl Otus scops (L.) (Aves: Strigiformes) from the Czech Republic, collected in 2011. Males are characterized by 10 pairs of caudal papillae, a single papilla on the upper lip of the cloaca, and small unequal spiculae; female distinguishing features are body length, distance of the vulva from the anterior extremity, tail length, and egg dimension.Analysis of the zoogeographical distribution and host specialization (in the bird orders) of 68 valid species from the genus Subulura Molin, 1860 shows significantly high species diversity in the tropical zones. Only one species, S. brumpti, is a cosmopolitan parasite of Gallus gallus f. domestica and other domesticated gallinaceous birds. Zoogeographical-host interactions may be utilized to support the identification of morphospecies of the genus Subulura.