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.