Internal audit quality is an issue of great importance to both the internal and external audit professions. PCAOB Auditing Standard No 2 highlights this importance when addressing the reliance that the external auditor can place on the internal audit work product. The study discussed here experimentally tests the influence of the source of the internal audit function on both the internal and external auditors\u27 evaluation of the quality of the internal audit function. To assess the importance of the internal audit function\u27s sourcing arrangement in the internal audit function\u27s quality assessment, the researchers employ a case study approach, modifying a case that has been used in prior research. The researchers find that for three of the four measured internal audit function quality characteristics, there was no difference in the assessment of the internal audit function between internal and external auditors, regardless of whether or not the internal audit function was provided in-house or was outsourced to a CPA firm other than the external auditor\u27s firm