The systematic importance of larval characters of the Neotropical genus Proceratophrys has been demonstrated. We review the internal anatomy of the tadpoles of the monophyletic P. bigibbosa species group, provide the first description of larval musculature and new data on the chondrocranial morphology, and describe the external morphology and buccopharyngeal anatomy of the tadpole of P. brauni. Our results support four larval synapomorphies for the P. bigibbosa species group (i.e., conical vent tube, dorsal fin originating in the body-tail junction, large gap on the second upper tooth row, and trapezoid median ridge on the buccal roof). The presence of a chondrified commissura quadrato-orbitalis, the processus pseudopterygoideus, and an enlarged element on the posterior margin of the hypobranchial plate near the attachment of ceratobranchial IV could be putative synapomorphies for Odontophrynidae.