This article analyses how populist parties wage opposition in parliament. We conceptualise opposition behaviour in terms of two independent dimensions: scrutiny (monitoring and criticising government actions) and policy-making (participating in or directly influencing legislative production). In line with the conceptualisation of populism as an opposition to the ruling elite in name of ‘the people’, our hypothesis is that populist opposition parties are more likely to use scrutiny and less likely to use policy-making tools than non-populist opposition parties. We study the Netherlands between 1998 and 2017 as a typical example of a consensus democracy, where populist parties have a greater opportunity to win representation and use parliamentary tools (compared to majoritarian democracies). Our findings indicate that populist opposition parties are particularly less likely to engage in policy-making behaviour and somewhat more likely to engage in scrutiny behaviour.