In this article, we address the problem of measuring the professionalism of political campaigns in national parliamentary and European Parliamentary elections by means of a comparative analysis. We use party-level campaign data from two fairly similar EU member states, Germany and Finland, and eight elections between 2004 and 2011. The data are used to build an index of campaign professionalism which significantly improves previous measures by giving more attention to various campaign strategies instead of focusing only on material resources. Theoretically, our analysis is based on the so-called party-centred theory of professionalism. We hypothesise that in addition to an increase in party-level campaign professionalism over time and higher levels of professionalism in campaigning in national parliamentary elections, professionalism is also positively associated with a party's size and its right-wing orientation. We find support for the time effect, party size and emphasis on national-level elections. However, contrary to our theoretical reasoning, the political left turns out to harbour the most professional parties.