Résumé:
This paper aims to shed light on the importance of the internal audit and its contribution in strengthening the internal control strengthening the internal control system inside firms. The case study is an oil company (NAFTAL) firm in Mostaganem. By using the questionnaire and personnel interview as a means of collecting required information. The main finding of this paper is that audit has a crucial role in the enforcement of the internal control system, which is an important element in adjusting the firm activity and directing it to adopt effective ways of management in order to attain the desired targets
