This thesis deals with the audit of annual financial statements, which is obligatory for corporations according to § 268 Abs 1 UGB and in particular with the auditor?s responsibilities regarding the auditing process. The annual audit can be seen as the most important mechanism to enforce the Austrian accounting standards and thus, it assures the credibility of publicized corporate information.In most cases, the reasons for accounting scandals can be found in fraudulent or mistaken statements. The auditor?s various responsibilities regarding the revelation of fraudulent and mistaken statements therefore are a special matter of interest. The required actions are only programmatically determined by law. For this reason, they shall be substantiated in particular on the basis of the relevant national standards on auditing of the ?Kammer der Wirtschaftstreuhänder? and the ?Institut Österreichischer Wirtschaftsprüfer?.The second chapter of the thesis covers the basic principles of auditing. Besides presenting the legal framework, the conceptual basics and the aims as well as the limitations of annual audits are presented. For example, the reasons for why also a correctly certified annual statement normally will not be completely free of any incorrectness are worked out.The third chapter describes the auditing process chronologically, from the submission of the essential data and documents, the scheduling and the execution of the audit to the result in form of an auditing report and the granting, respectively denial of the auditor?s certificate.Besides a summary, the final chapter goes for a critical reflection over the instrument ?annual audit? and gives an outlook on developments to be expected, especially on the European level.