Today's logistics processes and systems are characterised by an increasing complexity and complicatedness as well as the need for global networking to cope with the growing diversity of logistics problems. Because of this, knowledge is more and more becoming a competitive strategic resource in logistics, too. This is commonly accepted theory. But how far has implementation of knowledge management methods gone in the logistics practice? To what degree the supposed (theoretical) relevance of investments into knowledge and knowledge management matches the actual priority of several knowledge management activities as shown by the respective investment volume? How do knowledge-related investments change a company's logistics performance? In order to answer those questions, a study was run with logistics companies from different European countries. It focused on the relevance of knowledge and knowledge management for executing logistics processes, on the need of investment into knowledge and knowledge management activities in logistics, and on the eventually existent relationship between knowledge and logistics performance. As a result, a qualitative determination of the state-of-the-art in implementing and applying knowledge management in the logistics practice was produced. Specifically, severe differences between the realities in different countries turned out. Furthermore, a model has been developed and applied to analyse the impact of knowledge management on a company's logistics performance. This model contributes to an economic assessment of knowledge management and the analysis of its potentials. The paper presents results of this empirical study and draws conclusions on both the current state-of-implementation of knowledge management in the logistics sector and the suitability of the methodology and model used. In the end open questions are identified and needs for further research are determined.