|Abstract||Recent field and laboratory observations on Pipa aspera from central French Guiana have yielded new information on the morphology, ecology, reproductive habits, and relationships of this poorly known pipid frog from northeastern South America. Morphologically, P. aspera is most similar to P. arrabali, from which it differs in details of its cranial and postcranial osteology. The snout of P. aspera is less depressed than that of P. arrabali and the eye is proportionally larger in P. aspera than in P. arrabali; in addition, P. aspera has wide nostrils that are more narrowly separated from one another than an those of P. arrabali. A phylogenetic analysis reveals P. carvalhoi to be the sister taxon to [P. aspera + [P. arrabali + [P. snethlageae + P. pipa]]]. Like P. arrabali, P. aspera produces relatively few, large young that undergo their complete development on the back of the female. Pipa aspera differs from its congeners in its preferred habitat of freshwater pools in flowing streams on the slopes of massifs of the Guyana Shield.