Already in the past, the influence of Rating Agencies has been strongly criticized, such as in the Enron scandal or even in the Subprime Crisis. However, this thesis deals with the Sovereign Debt Crises and the question, if Rating Agencies have to blame, that some European countries are bankrupt. To answer that question, this thesis is divided into two sections. The first part is devoted to theoretical foundations and explanations and definitions of terms. Furthermore, the Sovereign Credit Ratings are described which are essential in the second part. Specifically, the evaluation factors of the Rating Agency Moody's are shown. Moreover there is a historical overview of the rating market and the three major agencies.The second part deals with the origin and the background of the current Sovereign Debt Crises. Main attention is paid to some of the PIIGS: Portugal, Ireland and Greece. It follows a presentation of the economic situation and a comparison of these three countries. The following chapter is the core of the thesis and answers the question if Rating Agencies are guilty that some European countries are bankrupt. This is done on the basis of an empirical study, where the historical rating results of the agency Moody?s are shown and compared with the actual economic data. Furthermore, the assessment criteria of this agency are described and analyzed.The last chapter is devoted to a critical examination of the current rating practice. In particular, the lack of transparency, conflicts of interest, lack of resources, limited competition and the establishment of a European Rating Agency are discussed. Finally, the conclusion shows the obtained results.