This article undertakes an empirical analysis of the internal organisation of the CDU along four key dimensions. First, it discusses the model of the 'cartel party', identifying its key features and then setting out four key questions to pose in relation to the CDU's internal organisation, to see whether it approximates to the 'cartel' paradigm. The questions of whether a centralisation of power is visible; whether professionalisation has occurred; whether there has been the anticipated weakening in the power of party functionaries; and whether the CDU has become reliant upon state finances are then answered in the empirical section of the article, drawing upon the author's primary research. It concludes that the 'cartel party' thesis fails in significant respects accurately to reflect the CDU's modern organisation. This is of interest to scholars of the CDU, but also offers some insights on the way in which the cartel party thesis fails adequately to develop an accurate account of internal party organisational change, in particular underestimating the ability of internal actors to thwart reforms, and also the potential functional usefulness of a decentralised party organisation.