Populist parties are often associated with extremism. However, the term ‘extremism’ is usually ill-defined and value-laden. Conceptual analysis will help to define populism as well as extremism in a more precise and value-neutral sense. Empirical analysis of the programmes of six Dutch and three Flemish parties suggests that populism does not entail extremism, even if it can be combined with it. The Centre Party and Centre Democrats as well as the Socialist Party and the Flemish Bloc may have displayed extremist as well as populist tendencies at some point. Yet the (more or less) populist parties Liveable Netherlands (Leefbaar Nederland), the List Pim Fortuyn, the Freedom Party, the movement Proud of the Netherlands (Trots op Nederland) and the List Dedecker should not be considered extremist.