Recently, there has been an increase in the knowledge concerning the presence and fate of perfluorinated compounds. They are known as ubiquitous environmental contaminants, which occur in wildlife tissues with relatively high concentrations. Even in remote (Arctic) areas FOCs are present in a great diversity of organisms in detectable concentrations. The presence of one of the most important perfluorinated compounds, namely PFOS, has already been described in the Scheldt estuary. In this study, we will focuss on other, related perfluorinated chemicals, as other compounds are also used in several industrial applications. This study will provide a basis for completing the picture of the presence and distribution of perfluorinated compounds in the Belgian and Dutch aquatic environment.