Today, we observe the importance of accuracy of financial statements in every corporation. Accounting scandals have caused important losses both in the macro and micro levels. This issue proves the significance of financial statement accuracy. This accuracy is provided by the trust environment. Therefore, it is necessary to provide the required environment of confidence for financial markets to improve and function effectively against increasing accounting frauds gradually. That can only be possible by using different auditing techniques, running inventory counting such as cash and stock, establishing strong internal controls, managing efficiently and benefiting from technology integrated auditing. The aim of this study is to investigate the most effective auditing techniques to avoid cost accounting frauds. In this research, the most effective auditing techniques for detecting and preventing fraud are investigated by using the case analysis method. Also, the well known scandals related with Olympus, Worldcom, Tesco, Sunbeam and Parmalat companies are examined as a part of the case analysis. Finally, recommendations and suggestions regarding fraud prevention methods are presented.