Background Important role of ethical behavior in organization, resulted in directing managers and experts to its affecting factors, since analysing the effective factors on ethical behavior of employees can improve it at different levels of organization. Therefore, the aim of this study was to analyze the factors that affect on ethical behavior of Mashhad Municipality employees. Method In this study, mix method (quality and quantitive) is used that in quantity is thye post hoc research. The study population includes all the employees of Mashhad Municipality in the center and the regions. The samples in the qualitative study, based on purposive sampling include 40 persons and samples in the quantitative study, based on random sampling were 327 persons. In order to gather information, interviews and questionnaires were used. The content analysis was used to analyze the interviews. Confirmatory factor analysis in AMOS was used for analysing data. Results The results show that the factors affecting ethical behavior of employees can be in the form of 12 components and 22 variables. By using KMO index and Bartlett's test the appropriate number of data was approved. In order to assess the research model, factor loadings were calculated and since all factor loadings were more than 0. 3 the research model was approved. Conclusion The results of this study show that the factors affecting ethical behavior of employees are including: Ethical personnel selection, Ethical compensation, Empowerment and socialization, Career, Ethical Team building, Ethical work environment, Organizational Justice, Motivation, Organizational Commitment, Ethical leadership style, Ethical structure and Ethical monitoring.