It is generally agreed that corruption is harmful in many different ways. Apart from the economic effects (as Mauro 1995, 1997; Rose-Ackermann, 1998) social and political consequences of corruption have received increased attention in contemporary national and cross-national research (Della Porta 2000; Uslaner 2004; Richey 2010). In the literature, it is argued that corruption violates the fundamental principles of democracy such as equality, fairness, transparency and accountability and threatens regime stability (Anderson a. Tverdova 2003; Sandholtz a. Koetzle 2000; Warren 2006; Basu 2006; Chang a. Chu 2006). This, in turn, may have perilous consequences for the legitimacy of a political system, particularly in new democracies (Rose et al. 1998; Rose-Ackerman 1999; Tulchin a. Espach 2000; Montinola a. Jackman 2002; Seligson 2002; Chang a. Chu 2006). However, prior to analysing the consequences of corruption it is indispensable to elicit different causes of corruption in a systematic way. On the basis of statistical analysis, this project develops a causal model that explains the level of corruption in “new” and “old” European democracies.