Proceedings of a workshop organised in response to a request of the Ministry of Housing, Spatial Planning and the Environment by the National Institute of Public Health and the Environment. To discuss the state-of-the-art in research on the interaction between contaminants and nutrients sixteen presentations of scientists from different countries have been concluded in the proceedings. Concluding remarks were: the lower the trophic state reached in combatting eutrophication, the more important the interaction of toxicants ; interactions are especially important when it comes to persistent hydrophobic substances and heavy metals ; although eutrophic systems act as a sink for toxic substances, it is not recommended to keep these systems eutrophied ; it is not recommended to give priority to either contaminants or eutrophication in emission reduction ; both have to be attacked simultaneously.