Much debate has focused on the significance of the "modern" cultural elements found in European Late Middle Paleolithic (Châtelperronian, Uluzzian, and Szeletian) contexts. In light of evidence suggesting cultural interaction between the makers of these industries and the makers of the Aurignacian (presumably anatomically modern humans) it is imperative that the taxonomic affiliation of the hominins associated with these "transitional" industries be accurately identified. The fossil remains from the Châtelperronian levels (VIII-X) at the Grotte du Renne (Arcy-sur-Cure, France) comprise a series of isolated teeth, as well as a child's temporal bone. While the temporal bone has been analyzed (and identified as having Neanderthal affinity), most of the 29 teeth from these levels have not been described. The Châtelperronian dental remains from the Grotte du Renne comprise both permanent and deciduous teeth. Fortunately, most are well preserved and relatively unworn. Simple dental dimensions are not particularly helpful in attempts to differentiate between Neanderthals and anatomically modern humans. The dimensions of the postcanine teeth in these two groups overlap completely. However, Neanderthals are known to have larger anterior teeth (on average), especially relative to their postcanine tooth size. Not surprisingly, we find that the crown dimensions for the postcanine teeth from the Grotte du Renne fall within the ranges of both hominin groups. The crown dimensions of the anterior teeth, however, strongly suggest that they belong to Neanderthal individuals. The buccolingual measurements of all but one tooth fall outside the range of Upper Paleolithic modern humans and within the range of Neanderthals. Research by the first author has identified key dental morphological features that can be used to differentiate Neanderthals and anatomically modern humans. These key characters are found in the upper incisors, upper molars, P4 and lower molars. Fortunately all but the upper molars are represented by the Châtelperronian remains at the Grotte du Renne. The strongly shoveled, labially convex lateral incisors with strong lingual tubercles, the asymmetrical P4 with a strong, mesially placed metaconid and multiple lingual cusps, and the presence of the mid-trigonid crest on lower molars all point to a Neanderthal affinity of these individuals. In addition, the morphology of the deciduous teeth more closely resembles that of Neanderthals than it does that of anatomically modern humans. There is no single dental morphological character present exclusively in Neanderthals. Rather, it is the frequency with which certain characters occur and, more importantly, the combinations of morphological features that are important diagnostic tools. The distinctive combinations of features characteristic of Neanderthal teeth are all found in the Châtelperronian-associated teeth from the Grotte du Renne. Our analysis of both the permanent and deciduous teeth, therefore, is in agreement with the analysis of the temporal bone indicating the makers of the Châtelperronian at the Grotte du Renne were Neanderthals.