The lack of consensus surrounding the macroscopic determination of high-quality black flint discovered at the Aldenhoven Plateau sites (Rhineland, North-Western Germany) from the beginning of the Middle Neolithic has far-reaching consequences for the anthropological understanding of the socio-cultural dynamics involved in the neolithization of North-Western Europe. This flint has been assigned to Western Belgian ‘Obourg’ flint type and is used as a key indicator of strong links between populations from West Belgium (Mons Basin) and the German Rhineland at the beginning of the 5th millennium BC. Here, we present an integrated study of this flint using geochemical and lithic technological approaches. This work rules out attribution of the analysed flint artefacts to the Upper Cretaceous flint sources of the Mons Basin; however, the exact origin of the black flint used in the Rhineland remains unanswered. Our results do not support the hypothesis of intensive contact between populations from West Belgium and the German Rhineland and highlights the urgent need for further combined petrographic and geochemical analyses in the region, particularly on geological samples, in order to build up an extensive and reliable comparative reference collection.