The purpose of this study is to demonstrate the importance of the concept of conservatism in accounting and corporate governance. Global scandals in recent years have brought distrust against accounting practices. The concept of conservatism, one of the factors that affect the practice of accounting, has impact on the reliability of the information presented in the financial statements together with corporate governance. In this study, the factors affecting the conservatism were studied using Eviews program in BIST 100 index companies. In this context, using panel data analysis method, the relationship between variables related to conservatism practices of companies was evaluated between the years of 2006-2013. At the end of the chapter, a general assessment was made about the obtained results and the relationship between them.