Companies can be successful if they are able to plan future strategies effective and efficiently and by presenting reliable and transparent investment environment to their shareholders. A stronger internal control system and a related department which evaluating the risks, optimizing and controlling the system and giving consulting service if it requires is crucial to achieve this success. The developments in some areas such as competitive environment and information technology and by increasing human resource requirements on growing companies, importance of internal control system is rising to take precaution on faulty, fraud, illegal and corruption subjects. Consequently, some suggestion made in terms of internal audit role on providing internal control system. Finally, the company's inspection, internal control and procurement proceses were examined at the interview with a construction company.