This thesis sets out to explore some questions about the nature of consultancy, the client organization and interactions between consultant and client that can make the journey akin to a tightrope walk - sometimes smooth and relatively uneventful, though still requiring considerable skill, at other times fraught with hazards. The main research question posed is What are the characteristics of consultants that might be significant in whether or not they make a difference? and this concerns factors about consultants, organizations and the interaction between them might affect whether or not a consultant can meet the client's needs. In addressing them, the thesis will identify some characteristics of consultants, aspects within organizations, and events at the consultant/client interface that can affect both the likelihood of a successful outcome and the smoothness of the tightrope walk. Here I shall introduce some factors in the very complicated mosaic of consultancy in action, and illustrate some of the characteristics of consultants and organizations that can contribute to the politics of consultancy. Some features of consultants and consultancy that might be significant in making a difference are reviewed. This will be set within a framework that illustrates the developing role of the management consultant and proposes that there are different approaches to consultancy. Some of these differences have come about as the profession has developed for example, from the Organizational Development approach to knowledge management strategies - while others are down to tactical differences between different styles, approaches and outcomes of consultancy. For example, some consultants make numerous contributions to the academic literature, developing and testing theory. Others produce just one or two best-selling books describing their approaches and solutions to management problems, while others do not publish anything at all. In considering these differences, we shall find evidence in support of the contention that one group of consultants, the management gurus, might be unable to bring lasting and beneficial change to an organization at all. Indeed, they might not even be able to bring about the kind of change that the client had in mind, even in the short term. I shall explain why and, in so doing, will make a contribution to the debate by supporting the criticisms made in the academic literature against the gurus. This is followed by a review of some organizational characteristics, beginning with why an organization might want to engage a consultant in the first place. It will also look at organizational features such as decision-making that might be significant in the organization's ability to translate the consultant's recommendations into action, and thereby ensure that a difference is made. This leads to a review of the different roles and priorities of consultants and organizations. Very little has been written about the consultant/client interface, yet in some cases this might be extremely significant to the outcome and in many instances it will be highly significant in the process. These three domains, the consultant, the organization, and the interface between the two, are discussed in the context of a (largely retrospective) case study undertaken as a part of the author's own work as a consultant in the specialist field of medical and dental education.