The tadpole of Telmatobius mayoloi from central Peru (Departamento de Ancash) is described based on specimens ranging from Gosner Stage 28-41. The tadpole of T. mayoloi is similar to other Telmatobius larvae with pond type morphology. Geographically closest to T. mayoloi are Telmatobius carrillae and Telmatobius rimac. The tadpole of T. mayoloi differs from the latter in reaching a maximum total length of 102.1 mm at Stage 38 whereas T. carrillae (maximum total length =99.20 mm at Stage 39) and T. rimac (maximum total length =77.70 mm at Stage 36) are smaller. Furthermore, the snout of the tadpole of T. mayoloi is slightly narrower between the nares, and its tip is pointed compared to the broader snouts of T. carrillae and T. rimac. The tadpole of T. mayoloi is the fourth largest in Telmatobiinae; data comparing tadpole total lengths and adult snout-vent lengths of Peruvian Telmatobiinae are presented. Copyright © 2009 Society for the Study of Amphibians and Reptiles.