PurposeUsing a sample of 250 Tunisian companies, this paper aims to assess the joint audit mission quality in Tunisia.Design/methodology/approachThe present work aimed at investigating the determining factors of the joint audit quality.FindingsA total of nine essential determining factors were predictably identified: length of service, experience, size asymmetry between the joint auditors, complexity, governance, expertise, information and communications technology use, profitability and staff qualification. However, results show that specialization, satisfaction, the supply of services other than audit, work distribution, leverage as well as size have a positive but non-significant correlation with the joint audit quality, which may be due to the Tunisian context.Originality/valueMany previous works have been conducted on joint audit in France (Haak et al., 2018), Denmark (Lesage et al., 2017), Germany (Velte and Azibi, 2015), Sweden (Zerni et al., 2012) and Italy (Bianchi et al., 2019). However, to the authors’ knowledge, the Tunisian context is still under-studied and, thus, the objective was to fill this gap in the literature b.y examining the determinants of the quality of joint audit in Tunisia.