Organizational Impact dimension of information system effectiveness has been a weak link in the information systems discipline. The simple reason has been the fact that any organizational study confronts us with a multiplicity of factors and inter-relationships. In the IS literature relating to information systems effectiveness, starting from 1992, the organizational perspective remained hard to conquer. In this case research, we try to understand how enterprise information systems like the Core Banking Solution (CBS) create changes in the organization. We start with the theoretical background of the study so as to draw the right boundaries for the study. The historical aspects of the organization and its IT systems are examined. Then the implementation of the core banking solution is studied to completely understand the changes in the organization as a result of a major IT change. We find that IT change has a profound impact on the organizational elements like organizational culture, structure and strategy and hence the change is more transformational and not just transactional. It is concluded that change in the enterprise information system can transform even a traditional banking company into a vibrant organization which uses the state of the art technology for providing high quality service to its customers.