The objectives of the present study are to provide information about the habitat, behaviour, and reproduction of the new European frog species Rana pyrenaica, endemic in the central and western Pyrenees, and to compare the breeding characteristics of R. pyrenaica with those of four amphibians present in the same geographical area (Rana temporaria, Alytes obstetricans, Euproctus asper, and Triturus helveticus). Unlike R. temporaria, A. obstetricans, and T. helveticus, which are typically found in standing waters and are rather ubiquitous species, R. pyrenaica is a stenothermic, rheophilous species. Small torrents with cold, well-oxygenated waters constitute its typical habitat. This species – which seems much more aquatic than R. temporaria – has been most often found in sympatry with the endemic urodele E. asper. Unlike R. temporaria, the females of R. pyrenaica lay small clutches of large eggs.