Uperolein is a tachykinin closely related to physalaemin and possessing the same spectrum of biological activity. Uperolein was present in the three species examined. Taudactylus contained a bradykinin-like peptide and both the Uperoleia species an hitherto unclassified peptide. These new findings have further enriched the already considerable list of active peptides and biogenic amines occurring in the amphibian skin.