Rhabdias leonae n. sp., a parasite of the lungs of Norops megapholidotus, is described and illustrated. The Mexican taxon differs from the other species in the genus by a combination of characters: possession of 4 lips, corpus slightly inflated, slightly postequatorial vulva, and presence of swollen cuticle of anterior and posterior ends. This is the 12th species described in the Neotropical realm and the first species of Rhabdias described from an endemic Mexican lizard.