The study was about assessing the effectiveness of internal audits in the Ministry of Culture and Fine Arts in Cambodian. The major objective of the study was to assess the effectiveness of Internal Audit in the Ministry of Culture and Fine Arts to identify the relationship between the effectiveness of internal audits and the factors that affect the effectiveness of the Ministry of Culture and Fine Arts with 96 respondents were selected the study used judgment sampling. The study concludes that despite the fact that the used to assess the effectiveness of internal audit show a high correlation to the effectiveness of the internal audit at the Ministry of Culture and Fine Arts is on average effective but the lack of control with auditees because the unit is understaffing and not being fully some risk management of risky internal control and financial, department structure, making position, documentation keeping, Implementation department plan, regular meeting plan, regulation and poverties management risk, that relationship between the effectiveness of Internal Audit and financial performance of the Ministry of Culture and Fine Artâ€™s result indicated that, the internal control system is depending on other factors include the Ministry of Culture and Fine Arts should increase both monetary and non-monetary support to internal audit activities in order for them to handle their activities effectively. Auditors should improve the quality of audit work in order for them to add value to their organizations. Auditors responsible for the Internal Audit Department and auditees should increase for internal audit budget in order to complete their activities as planned.