Purpose - The purpose of this study is to shed light on one part of the external auditor’s work by examining how the cooperation between external auditors and internal auditors is organized and if external auditors face a dilemma when cooperating with internal auditors. The focus will therefore be on what aspects are considered by the external auditor in the decision to cooperate with internal auditors (and to use their work), as well as how the external auditor safeguards the audit quality by maintaining an independently and professionally executed audit.

Design/methodology/approach - This study was realized through a qualitative research method. Semi-structured interviews were conducted with external auditors that have engagements with internal audit functions. All respondents are employed in the Big 4 and are operating in Sweden.

Findings - The results of the study show that external auditors tend to use the work of internal auditors when they cooperate. To gain efficiency improvements is the main beneficial aspect the external auditors consider in the cooperation with internal auditors. The findings would suggest that some external auditors may act after self-interest more than others because if they start the cooperation and spend the time to evaluate the internal auditors’ work, they would prefer to use it. This would also indicate that the external auditors’ independence and professionalism can to some extent be compromised because there seems to be an acceptance of a certain degree of lower audit quality when using the work of internal auditors.

Originality/value - The use of semi-structured interviews makes it possible to obtain deeper knowledge and complement prior studies concerning cooperation in the audit industry and how the external auditor considers different aspects in a decision-making environment.