Investigation Factors Affecting the Effectiveness of Internal Auditors in the Company: Case Study Iran

There are relatively fewer number of studies focused on internal audit effectiveness, than the number of studies on the effectiveness of external audit. Our focus in this paper is mainly on determinants of internal audit effectiveness. For this purpose we developed and tested five hypotheses using an investigation approach. We gathered our data using a questionnaire, filled out by 355 internal audit manager and 272 other internal audit staff.

Our multivariate regression model estimates the relationships between the effectiveness of internal audit department and its five main determinants: competency of internal audit staff, size of internal audit department, communications between internal auditors and external auditors, management’s support for internal audit department, and independent (outsourced) internal audit.

Our results show that internal audit effectiveness has stronger relationships with management’s support for hiring and experienced educated staff, providing the internal audit department with sufficient resources, and the size of internal audit department.