A thorough assessment of the sustainability performance of a product, a system, or a decision requires expertise on environmental, economic, and social aspects. In an assessment that involves researchers from different disciplines, communication is challenging because of different background knowledge, terminology, research traditions, etc.In the research program Towards Sustainable Waste Management, a new approach to interdisciplinary interaction was tested. The program included a group of researchers on life cycle assessment (LCA) and systems analysis of waste management. To this group, specialists in national economy, environmental psychology, and ethnology were linked in various projects. In each specific research project at least 20% of the budget was allocated to a waste LCA expert, who, through participating actively in the project, would be an interpreter, a two-way bridge between the disciplines. The first purpose of this LCA expert was to interpret the sustainability questions and to help make the research relevant for the overall purpose of the research program. The second purpose was to interpret the results of the specialists’ research and to help making the results useful for the overall program.Our experience demonstrates that this set-up forces the specialists and their interpreters/bridges to face the challenge of understanding each other. Establishing such an interdisciplinary interaction requires that the researchers share a mutual interest in trying to reach understanding. However, despite this interest and despite the significant resources made available for the participation, our collaboration was restricted by the fact that it can be difficult for the specialists to find suitable tasks in their projects for the LCA expert. The chance of the interaction being successful increases if the background knowledge of the researchers in the project overlaps, if they have similar research cultures, if they share a common interest in the research questions, and/or if the disciplinary scientists are accustomed to interdisciplinary collaboration.