Bufotenin (5-hydroxy-N,N-dimetyltryptamine) is a tryptamine alkaloid widely spread among anuran families as a component of their chemical defense system, acting as a potent hallucinogenic factor, showing similar activity to LSD upon interaction with the 5HT2 human receptor. This work demonstrates the presence of bufotenin in the skin secretion of three arboreal amphibian species of the Osteocephalus genus (Osteocephalus taurinus, Osteocephalus oophagus and Osteocephalus langsdorffii) from the Amazon and the Atlantic rain forests using RP-HPLC, ESI–MS/MS, UV, IR and multidimensional NMR techniques. To our knowledge, this is the first description of bufotenin in the Osteocephalus genus, so far.