Species distribution models are increasingly important in herpetological studies of spatial ecology and conservation. In this paper, we estimate the potential distribution of an endemic and threatened Mexican lizard, Plestiodon copei. The presence of this skink was estimated using the maximum entropy algorithm, and the most relevant environmental variables for the model were identified. Additionally, the specialization of the species was evaluated, the coverage of natural protected areas throughout its distribution was estimated, and the priority areas for the conservation of this lizard were delimited. The model shows that the optimum areas of distribution extend from the southeastern state of Jalisco within the Faja Volcánica Transmexicana (FVT) to the limits of the states of Puebla and Veracruz, covering an area of approximately 12,300 km^2. The distribution of P. copei was associated with high mountains and temperate forests, ecosystems strongly affected by human activities. The model predicted previously unrecorded populations, some of which were corroborated in the field. It was also found that 53.08% of the species' distribution is within natural protected areas along the FVT. These observations emphasize the urgent need to propose conservation strategies for this endemic lizard and its habitat.