Business today are facing great challenges and complications than ever before, as economical, legal and technological interdependence become more common and pronounced. Due to these developments, risks may go unidentified too long and early warning indicators ignored. It is therefore an assumption that every business organisation has put in place risk management and internal control systems in order for the organization to continue running. In light of this, this paper has been undertaken in order to present more about the internal control systems implemented by companies and the part of internal audit inside those systems. My thesis is a study of the need that every organisation has. The study is made by examining the theoretical field of knowledge that I had access to. This study reveals that control systems exist in the company and that these control systems are very important, effective and therefore provide adequate checks and balances.