In June 2005, 61.5% of the Dutch voted ‘nee’ in the referendum on the European constitution. In the present contribution I test hypotheses from the national identity, utilitarian and political approaches to explain this voting behaviour. I collected data in the Netherlands to test whether one of those approaches has been decisive in explaining the referendum outcome. I also provide information about whether specific EU evaluations from these approaches explain the voting behaviour, thus bringing in the discussion on the importance of domestic political evaluations (second-order election effects). I also test hypotheses on which theoretical approach explains differences between social categories in rejecting the constitution. My results show that specifically EU evaluations in particular accounted for the ‘no’ vote, although in conjunction with a strong effect from domestic political evaluations. I also find evidence for ‘party-following behaviour’ irrespective of people’s attitudes. Utilitarian explanations determine the ‘no’ vote less well than political or national identity explanations. The strongest impact on voting ‘no’ came from a perceived threat from the EU to Dutch culture.