A new species of hylid frog, genus Osteocephalus is described from the eastern Andean slopes of central Peru (Pozuzo, Departamento Pasco) between 780 and 1000 m above sea level. It differs from all other species in the genus by the following combination of characters: small size, smooth dorsum in males, bicoloured iris lacking radiating dark lines, but finely reticulate ventrally, light, pale nuptial pads not keratinized, and subgular vocal sac. Females of the new species are unknown.