Organizational diagnosis is the process in which a behavioral science assumption is based on human system in an organization; suitable data are gathered concerning human experiences in that system. After this information is collected, it is fed back to the system for the promotion of the increased comprehension of the system by its members. Generally, organizational diagnosis is a process of analyzing an organization in order to identify the strengths and weaknesses of its system and processes and use it for improving its effectiveness. On this basis, the main purpose of organizational diagnosis is the establishment of an extensively shared understanding of a system or an organization and agree on whether change is required based on the understanding gained. In this case, this study will reports on the organizational diagnosis of a Bank in the department of human relations under accounting system which need to be change as a result of poor management and human relations (Weisbord, 1978).