Changes in Dutch attitudes towards the European Union For decades, the Dutch were seen as relatively positive towards the European Union. However, in 2005 a majority of the Dutch population voted against the proposed European Constitution. Therefore, in this article we examine to what extent the Dutch ‘no’ marks a sudden change in attitudes, or is merely a manifestation of a gradual trend that started at an earlier stage of the European integration process. We raise the question to what extent attitudes towards the European Union have changed in the Netherlands, and further ask to what extent these changes can be attributed to characteristics of the context and the life course. We derive hypotheses from theories on the influence of birth cohort, societal context and life course on attitude changes. In order to test these hypotheses, we employ Eurobarometersurveys of 1973 to 2004, as well as additional data at the contextual level. Our findings suggest that in the Netherlands attitudes towards the European Union have become more negative since the early nineties, after becoming more positive in the preceding years. While characteristics of the birth cohort and the life course do not account for these changes, the development towards more political integration seems to provide an interesting explanation. However, even after adding respondents’ characteristics at the individual level to our models, variance in attitudes towards the European Union is hardly explained. Even though differences between social groups exist, attitudes towards the European Union seem to be largely unexplained.