We test the theory of expressive voting in relation to political ideology in a laboratory experiment. After deriving our hypotheses from a decision theoretic model, we examine voting decisions in an experiment in which we use the size of the electorate as the treatment variable. Using a Heckman selection model that includes both the electoral participation decision and voting choice decision, we find mixed results for the expressive voting hypothesis. In line with expressive voting, our findings suggest that non-ideological voters are more likely to abstain from voting than ideological voters – especially when the electorate grows large. Concerning the voting choice decision between an equal but inefficient, and an unequal but efficient income distribution the evidence for expressive voting is mixed. We do find that voters with socialist (left wing) preferences behave expressively, but we do not find this effect for voters with capitalist preferences.