Both academics and practitioners have invested considerably in the information systems evaluation arena, yet rewards remain elusive. The aim of this paper is to provide rich insights into the process of IS evaluation by examining some particular political and social aspects of evaluation processes. An ethnographic study of a large, international financial institution is used to compare the experience of observed practice with the rhetoric of company policy, and also to contrast these observations with the process of IS evaluation as portrayed within the literature. Our study shows that despite increasing acknowledgement within the IS evaluation literature of the limitations and flaws of the positivist approach, this shift in focus towards interpretivist understanding has had little impact on organizational practice. In addition, our observations within the research site reveal that the assumed rationality of formalised evaluation processes merely obscures issues of power and politics that are enmeshed within these processes.