In the past, the tragulid species Dorcatherium crassum has been considered a synonym of Dorcatherium naui, although they are currently considered distinct species. The former has an exclusively Aragonian (MN4 to MN6) stratigraphic range, whereas D. naui is considered a typically Vallesian species (MN9 and MN10) that survives until the Turolian (MN11). There are only a few previous citations of Dorcatherium from the European latest Aragonian (MN7+8), and only that of Przeworno (Poland) can be securely attributed to D. naui. Here we describe dentognathic and postcranial remains of Dorcatherium from several localities from the stratigraphic series of the Abocador de Can Mata (ACM), in els Hostalets de Pierola (Vallès-Penedès Basin, Catalonia, Spain). These Dorcatherium remains, from both the lower (ca. 11.9-12.5 Ma, MN7) and upper (ca. 11.6 Ma, MN8) portions of the ACM series, constitute the earliest record of D. naui from the Iberian Peninsula and Western Europe. They most closely resemble D. naui from the Vallesian, but still share several features with D. crassum. On the basis of the unique combination of features displayed by the ACM material, a new subspecies, D. naui meini is erected. Its distinct status from the nominotypical subspecies, D. naui naui, is reinforced by the chronological differences between the two taxa. The morphological similarities between Dorcatherium and the extant water chevrotain ( Hyemoschus aquaticus) tentatively suggest the presence of forested and humid paleoenvironments in this area of the Vallès-Penedès Basin during the latest Aragonian. Nevertheless, Dorcatherium is very rare in ACM and displays a very patchy chronological distribution. Together with the similarly spotty distribution of both primates and castorids along the ACM series, this suggests that very humid conditions might have been only intermittently present in this area throughout the latest Aragonian.