In the challenging environment of the auditing profession, where maintaining quality and observing professional standards are considered essential pillars of public trust, it is of particular importance to identify the factors affecting auditors' professional behaviors. Understanding this necessity, this study examines the relationship between coherent self-knowledge as a deep psychological construct and audit quality-reducing behaviors. The main objective of this study is to explain the mechanisms through which coherent self-knowledge can act as a deterrent against quality-reducing behaviors and ultimately lead to improving the quality level of audit services. In this study, content analysis was used to determine the dimensions of auditors' coherent self-knowledge based on a review of previous studies and interviews with experts, and then data on this variable was collected through a researcher-made questionnaire. A standard questionnaire was also used to measure audit quality-reducing behaviors. In addition, structural equation modeling using partial least squares (PLS-SEM) was used to test the research hypothesis. In the qualitative part, 14 academic experts and audit professors with professional experience in the field of auditing participated in the interview, and the participants in the quantitative part, to test the research hypothesis, included 392 auditors working in the audit organization and private sector institutions in the first half of 1404. The results of the present study indicated 4 overarching themes (professional cognitive structures, individual disciplinary requirements, role perceptions in the financial ecosystem, and intrinsic motivational frameworks), 11 organizing themes (auditors' analytical insight, professional