Phlebotomine sand flies are the main vectors of human leishmaniases worldwide. Many studies have focused on the epidemiological aspects of sand fly vectors as well as other important ecological parameters. In several papers there have been reports of sand fly species collected in caves. Nonetheless, nothing is known about these species in México. The objective in the present study was to document the species composition and daily activity of sand flies inhabiting a karstic cave in the state of Yucatan. A total of 703 sand flies was collected comprised of seven species from the genera Brumptomyia and Lutzomyia. These results represent the first collections conducted from Mexican caves. The predominant species inside the cave was Lu. trinidadensis (47.51%); the activity of Lu. trinidadensis exhibited a major peak between the time period of 1600 to 2000 h, whereas Lu. beltrani displayed the highest activity peak between 2000 to 0000 h.