The development of exchange networks over vast distances is one of the most significant characteristics of Neolithic societies. The transition to sedentary agricultural societies is often associated with a considerable increase in the quantity of goods diffused and the distances they travelled. In Europe, and more particularly in the northwestern Mediterranean region, the phenomenon attained its apogee during the period of the Chassey culture (Middle Neolithic II). In this context, obsidian originating from the Mediterranean islands (Sardinia, Lipari, Palmarola and Pantelleria) provides interesting information due to its vast diffusion into the northern African continent, the Italian peninsula, the Midi region of France and the Iberian Peninsula, thus demonstrating the practice of navigation. Numerous models have been proposed to explain this diffusion, which created relationships of interdependency between communities separated by great distances. The recent discovery of the Chassey culture site of Terres Longues in the Midi region has renewed our vision of this phenomenon and encourages us to imagine other modes for the functioning of exchange networks during this period.