Effective internal audit is an important and integral function of organizations that helps in achieving its objectives and protecting organization's assets. Nonetheless, internal audit effectiveness has received little attention in the literature, especially in the context of developing countries such as Nigeria. This study examined the determinants of internal audit effectiveness in Kano state Ministries, Departments and Agencies. The study used Krejcie and Morgan to arrive at a sample size of 132 using the chief internal auditor and his deputy in each of the sampled Ministries, Departments and Agencies. 

The questionnaires prepared based on 5 Likert type scale and were distributed among the respondents. The data were analyzed using OLS multiple regression technique. The result revealed that independence of internal audit department has positive and significant effect on internal audit effectiveness of Kano State Ministries, Departments and Agencies. Management support for internal audit has positive and significant determinants on internal audit effectiveness of the Ministries, Departments and Agencies. However, competence of internal audit staff, size of internal audit department and relationship between internal and external auditors were also found to have insignificant influence on internal audit effectiveness. 

The study concluded that independence of internal audit department and management support for internal audit are the main factors that explained internal audit effectiveness of Kano state Ministries, Departments and Agencies. Therefore, regulatory authorities (Head of Service, Secretary to state government and ministry of finance) should work towards ensuring competent personnel in internal audit departments because the low level of professional qualifications and rapid rotation of employees to and from the internal audit department results in internal auditors (excluding directors) having low levels of experience in auditing.

Based on the findings, the study recommended that the regulatory authorities should ensure effective monitoring of competence of internal audit staff and increase management support for internal audit of the state Ministries, Departments and Agencies.