This study aimed to evaluate the infection rates of snakes by pentastomids in the semi-arid region of Brazil. Fifteen snakes (four Micrurus ibiboboca (Merrem, 1820) and eleven Philodryas nattereri Steindachner, 1870) were collected between January and April of 2005, in the municipality of Crato (07° 14' S and 39° 24' W), State of Ceará, Brazil. Laboratorial analysis of the respiratory tracts of the sampled snakes indicated differences in host infection rates: four individuals of P. nattereri (36.4%) were infected by Cephalobaena tetrapoda Heymons, 1922 (mean infection intensity 1.5 ± 0.28, 1-2) and three specimens (27.3%) by Raillietiella furcocerca (Diesing, 1863) (2.3 ± 1.32, 1-5). Only one individual of M. ibiboboca (25%) was infected by a non-identified species of Raillietiella sp. These are the first data on pentastomid infection in snakes in Northeastern Brazil and both snake species comprise new host records for the pentastomids. The results also indicate that the generalist parasites C. tetrapoda and R. furcocerca share their definitive hosts.