Background: Awareness of prioritizing the variables affecting the threat to the security and financial health of a bank is a very important issue. Also, the appropriate and ethical use of the set priorities is a more important issue in decisions related to the merger of branches with continuous losses. The purpose of this study is to investigate the fundamental factors affecting the formation and development of loss syndrome in Bank Mellat branches with emphasis on ethical variables. Method: The present study was qualitative and based on the data foundation approach. The statistical population included experts in the field of planning, decision-making and strategic decision-making of Bank Mellat, from which 21 people were purposefully selected as a sample. The analysis tool was interview and the data were analyzed using open, axial and selective coding. Results: The results of open and axial coding were the estimation of 53 initial codes in the form of 11 categories out of 280 concepts which were finally positioned in the research model using selective coding. Conclusion: In addition to conditions such as general economic conditions and inefficient management practices, inefficient decisions, lack of efficient regulatory and judicial systems, declining quality of banking services, etc., ethics can be an important factor in the occurrence of bank loss syndrome.
