In this paper a new, small species of Telmatobius from the Department of Ancash, Peru, is described. Telmatobius carrillae sp. n. is compared to T. brevipes Vellard and T. marmoratus (Dumeril & Bibron), which are distinctly larger. Though morphologically similar to Batrachophrynus brachidactylus Peters, its chromosomic features indicate that it belongs in Telmatobius, T. carrillae could represent a connecting link between Batrachophrynus and Telmatobius.