The Paleozoic vertebrate fossil record from Mexico is very scarce and strongly biased by rock exposure, composed mainly of upper Paleozoic (Carboniferous and Permian) outcrops (e.g., Sánchez-Zavala et al., 1999; Poole et al., 2005; González- Rodríguez et al., 2013). In particular, the Mexican Paleozoic fish fossil record comprises a few isolated chondrichthyan scales and some semiarticulated symphysial tooth whorls belonging to the iconic shark Helicoprion, with ages ranging from the Late Carboniferous to the early Permian. The first reported Paleozoic fish from Mexico belongs to a semiarticulated symphysial tooth whorl of Helicoprion mexicanus from the Permian of Coahuila, near Las Delicias County, originally described by Mülleried (1945) and subsequently republished by Applegate (1989). A second Helicoprion tooth whorl (not formally named) was discovered in Mina Plomosas (central-west Chihuahua) and dated as Wolfcampian (early Permian in age) (Bridges and De Ford, 1961). More recently, a third Helicoprion specimen, consisting of one broken symphysial tooth whorl, was reported by Sour-Tovar et al. (1991) in the Leonardian (Permian) of Patlanoaya Formation (Puebla, central Mexico) and described in detail by Sour-Tovar et al. (2000). In addition to those remains, a few isolated chondrichthyan microichthyoliths have been described, first by Brunner (1987) and later by Derycke-Khatir et al. (2005), from the Upper Pennsylvanian and lower Permian Patlanoaya Formation. The few studied dermal denticles have been identified as belonging to Cooperella typicalis, Moreyella typicalis, 'Sturgeonella' quinqueloba, and probably a hybodontid shark. To date, these studies represent the complete record of vertebrate remains known from the Paleozoic rocks of Mexico, emphasizing its scarcity and hence the importance of expanding our knowledge of this vertebrate fossil record. In this context, here we describe new Famennian (Late Devonian) fish remains, represented by isolated chondrichthyan teeth, from Cerro Las Pintas in the municipality of Fronteras, northeast Sonora, Mexico. This finding represents not only the oldest fish record but also the oldest vertebrate remains found in Mexico. The study of the chondrichthyan assemblage, although scarce, shows a relative diverse community comparable to the one described for similar ages in neighboring regions.