This article analyses how populist parties wage opposition in parliament. The authors 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 inname of ‘the people’, the authors 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. Otjes and Louwerse study the Netherlands between 1998 and 2017 as a typical example of a consensus democracy, wherepopulist parties have a greater opportunity to win r...