In the Late Middle Palaeolithic, the variability of Neanderthals’ lithic technologies in Central and Eastern Europe was complemented by a specific asymmetric tool type – the so called Keilmesser. Due to their morphological characteristics and interpretation as tools in purported long-term use, Keilmesser provide a unique archive for tracing late Neanderthal behavioural features. These may range from understanding tool design, production and dedication, to tool function, use and maintenance, along with aspects of technical innovations and transmission of skills and knowledge. Three Keilmesser assemblages from the sites of Buhlen, Balver Höhle (both Germany) and La Grotte de Ramioul (Belgium) were analysed. Applying functional analysis combined with controlled experiments in a multidisciplinary approach, published interpretations were tested and evaluated. The study presented in this book offers a blueprint to a more holistic approach by systematically employing different methods and scales of analysis. This comprehensive view on Keilmesser opens up room for discussions by offering a new perspective on this and, potentially, other specific tool types.