The research aims to know the role of internal auditing in evaluating the performance of service departments. Internal auditing is one of the most important functions that service departments focus on because of its impact on measuring and evaluating efficiency. The system is also considered one of the most important elements that the auditor relies on when performing the audit process, and because of an organizational plan, means, procedures and components through which it aims to protect its assets, ensure their use, and implement the established plans in a way that facilitates the achievement of its goals and in a sound scientific manner. We also mention the most important findings of the study:

1.There is an urgent need to modernize the monitoring methods carried out by the highest regulatory authorities.

2.Internal auditing is considered a set of internal laws, written and unwritten procedures, administrative directives, and work methods that contribute to better auditing in institutions.

3.It contributes to providing guarantees to increase efficiency and commitment in applying the job performance law.

4.The performance evaluation is an indicator of what the economic unit has achieved as a result of carrying out its administrative and financial activities in comparison with previous periods or with planned goals.