Recent events, such as failed constitutional referenda, low voting turnout in the European Union parliamentary elections, and the 2016 Brexit referendum in the United Kingdom call for a better understanding of people’s voting behavior in relation to the EU. The current study is the first attempt to use the theory of planned behavior to explore the antecedents of voting for EU integration in an Italian convenience sample (N = 441) of varying age. A structural equation model of voting intentions showed an excellent fit to the data, both for the whole sample and for subsamples of young vs. old participants. Perceived behavioral control, mainly determined by participants’ beliefs about the difficulties of exerting direct democratic control through citizenship and voting, had a significant effect on intentions to vote in favor of EU integration across age groups. In addition, older people’s intentions were also affected by their attitude towards EU integration, based primarily on their beliefs about losing national identity.