A large amount of studies already focused on auditor choice, which includes both the choice to hire an auditor voluntary (Dedman et al., 2014; Collis et al., 2004) and the choice to hire a high-quality auditor for firms with a statutory audit requirement (Firth and Smith, 1992; Piot, 2001; Lennox, 2005; Matonti et al., 2016). These studies mainly consider the shareholder–manager and shareholder–debtholder relationship to explain this choice. According to agency theory, auditing acts “[…] as a monitoring or bonding device dedicated to preventing and regulating conflicts of interests […]” (Piot, 2005, p. 23) that can arise between the shareholders and managers and between the shareholders and debtholders of a company (Jensen and Meckling, 1976). Therefore, the higher the (potential) level of agency conflicts between shareholders and managers on the one hand and shareholders–debtholders on the other, the higher the demand for an (high quality) auditor. While the agency relationships between a firm’s management and both its shareholders and debtholders proved valuable in explaining auditor choice, we argue that a firm’s other stakeholders may affect this choice as well. In this study, we therefore examine the auditor choice effect of the firm’s main supplier, customer and competitor. While the influence of these stakeholders on the firms’ auditor choice could also partly be explained by agency theory (e.g. regarding suppliers, which are also debtholders), we argue that the inclusion of the institutional theory is able to provide us with an additional view about their influence on auditor choice. More specifically, while the agency theory considers auditor choice to be a direct reflection of the level of agency conflicts and therefore considers it to be a well-defined solution to a well-defined problem, the institutional theory mainly focuses on problems with ambiguous causes and unclear solutions (DiMaggio and Powell, 1983). More specifically, the institutional theory states that firms may become very similar to one another as a response to uncertainty, pressures from stakeholders, external expectations, etc. (DiMaggio and Powell, 1983), which is called institutional isomorphism. Therefore, high-quality auditors may also be hired as a response to one of their main stakeholders hiring a high-quality auditor, irrespective of the level of agency conflicts, because this seems the best thing to do in an uncertain environment as it is considered to be good practice and might therefore increase the firm’s overall legitimacy.