In this paper we describe a new species of toad of the genus Incilius. This species was originally recorded as Bufo simus, a synonym of I. occidentalis. It differs from I. occidentalis by having the following combination of characters: a pale brown dorsal ground color with numerous dark brown spots and lacking a vertebral stripe and a high density of granules on the dorsum producing a rugose skin texture. The most developed of the cranial crests is the supraorbital, while the parietal is poorly developed. Incilius mccoyi inhabits pine and pine-oak forests of the southwestern Sierra Madre Occidental in Chihuahua, Mexico.