The purpose: The purpose of this research is to identify the key factors that affect ethical behaviour in the schools in Kuwait, and to present a conceptual framework of ethical behaviour at the workplace applicable to the education system of Kuwait. The model of ethical behaviour was developed by adapting several theories and models. Design, Methodology, and approach: The researcher follows the Critical Realism philosophical approach in the current study, which justifies the use of a methodology to conduct the research. This research utilizes sequential exploratory mixed methods design; the research involves two sequential stages, qualitative and quantitative stages. The study starts with the qualitative stage followed by the quantitative stage. Moreover, the study employs mixed methods research, which is a procedure for collecting, analyzing and combining both quantitative and qualitative data at some stage of the research procedure within a single study. The data collected by means of face-to-face and semi-structured interviews such as in depth interviews, followed by a questionnaire survey. The respondents represented teachers working in the Kuwaiti schools. Findings: The current study found a significant relationship between the independent variables of the organizational ethical culture such as sanctions, congruence of supervisors, feasibility, discussability, supportability and ethical leadership and the dependent variable of ethical behaviour. Moreover, the study revealed a significant relationship between the independent variables of personal ethical tendencies such as idealistic tendencies, relativistic tendencies and utilitarianism and the dependent variable. In addition, the study found a significant relationship between the independent variables of both greed and the national culture such as religious beliefs and wasta(favouritism) and the dependent variable of ethical behaviour. The analysis of the results ended up to the final model of ethical behaviour. Originality and Value of the Research :To the knowledge of the authors, this type of research is conducted for the first time in the private and public schools in the state of Kuwait. The empirical study differentiated a model of ethical behaviour valid for the education system in Kuwait and attempts to reinforce ethical behaviour and combat the widespread unethical behaviour in Kuwait as wasta (favouritism) and greed.