Telecommunications systems seem to offer health care providers, professionals and patients a plethora of opportunities to respond to social and geographical inequalities in health care provision, and a new field of health care endeavor has emerged--'telemedicine'. This paper presents results from a three year ethnographic study of the development and implementation of telemedicine systems in a British region. We explore how attempts to put into service one 'telemedicine' system failed to get beyond the draft of a written protocol. Our analysis focuses on the contests between clinicians, technical experts and external evaluators over what kinds of knowledge and practice count in developing a protocol and evaluating a clinical intervention. We show how the introduction and implementation of 'hard' technologies (systems hardware) can be undermined in practice by 'soft' technologies (the practices through which evaluative knowledge is produced).