The university accreditation system in Chile appears to be influenced by tensions between interest groups from well-established institutions and newer (private) institutions. These institutions depend to a certain extent on accreditation decisions to obtain indirect public funding. However, the system relies on faculty nominated by conglomerates formed by these same institutions to decide on accreditation. This arrangement creates a potential conflict of interest that can jeopardize the accreditation's legitimacy. We explore this potential bias through an empirical study examining voting behaviour by commissioners of the Chilean National Commission of Accreditation from March 2013 to October 2016. We assess whether commissioners appeared as favouring institutions within their appointing conglomerates. To our knowledge, this is the first study in the region designed to examine the presence of bias in higher education accreditation. Findings indicate commissioners, on average, tended to favour institutions in their appointing conglomerates. We discuss the findings in the broader context of a forthcoming reform of the accreditation system.