This study concerns lithic technical systems during the Middle Palaeolithic (Final Glaciation) in the north-east Aquitaine basin (France). The analytical approach is based on a paradigm which shows the complexity of production schemes by technical and economical perspectives ('branched' chaîne opératoire). The results of this study show self-sufficient organizations of lithic production systems: each, with its own technical specifics, shows techno-economical adaptations in relation to differing eco-functional objectives achieved in different environments. This Mousterian lithic production approach gives a new understanding of the Mousterian variability in this landscape. The analysis adopted (technical and economic behaviour) also presents questions about stability or diversity of technical knowledge and economic understanding as practised by Mousterian groups during the Final Glaciation period.