Do attitudes towards European integration influence vote choice in national elections — a phenomenon I refer to as European Union (EU) issue voting? Evidence concerning EU issue voting is thus far mixed. Some scholars conclude that an electoral connection exists between European and national politics, whereas others claim that European integration has had very few observable effects on national elections. A resolution emerges when the conditional nature of EU issue voting is acknowledged. Specifically, EU issue voting is more likely to occur in elections in which both the extent of partisan conflict over European integration and the degree of EU issue salience among voters are high. Using a conditional logit model, I illustrate the conditional nature of EU issue voting by comparing UK, Danish, Dutch and German elections between 1992 and 2002.