Arenysaurus ardevoli is a lambeosaurine hadrosaurid from the late Maastrichtian of Arén (Huesca, northern Spain) that has recently been described. The holotype is the first and the most complete lambeosaurine with a braincase from Europe. In this paper, we present a complete description of the postcranial skeleton, which was poorly described when the taxon was named because it was partially unprepared, and new information on several cranial bones (jugal, maxilla, and dentition). A new phylogenetic analysis of Arenysaurus and the closely related Blasisaurus canudoi, also from the late Maastrichtian of Arén, places them inside the Parasaurolophini in a dichotomy with Parasaurolophus spp. Paleobiogeographically, the presence of Arenysaurus and its relationships with other lambeosaurines suggest at least one geodispersal event from Asia to Europe no later than the middle—late Campanian.