Previous studies have used different approaches to investigate the internal audit effectiveness. Some (Al Darwish, 1990; Twaijry et al., 2003) adopted International Standards for Professional Practice of Internal Auditing (ISPPIA) as a guideline to investigate and determine internal audit effectiveness while others (Mihret & Yismaw, 2007; Arena & Azzone, 2009; Ahmad et al., 2009) developed their own models to determine internal audit effectiveness. Moreover, in the literature, factors and the measurement of effectiveness have been used differently among the researchers (Arena & Azzone, 2009); and until today, there is no consensus on the best framework for effectiveness. Until the early 1990s, there was limited research about internal audit effectiveness. Boyle (1993) examined six major academic accounting journals for the period from 1975 to 1990, and found only twenty-one articles on the subject of internal audit and none of them dealt with internal audit effectiveness. This limitation is mainly related to lack of sufficient attention to the theories which could serve to build a theoretical framework of internal audit effectiveness. Adams (1994) confirms that the agency theory contributes to: a) rich and meaningful internal auditing research; b) explaining the existence of internal audit, its nature and the approach which is adopted; and c) predicting how internal auditors will be affected by organizational restructuring and rationalization. Mihret et al. (2010) have argued that, there is a positive association between compliance with ISPPIA and organizational goal achievement that could serve to evaluate internal audit effectiveness. On the same note, the current paper suggests a combination of theories which could of help in developing a theoretical framework of internal audit effectiveness and extend the internal audit research that include: agency theory, institutional theory, and communication theory. The following sections provide the theoretical perspectives, literature review and propositions, theoretical framework of internal audit effectiveness, followed by discussions and research conclusion.