A case study analysis of the introduction of a new system for appraising worker performance in an Australian coal mine is used to explore the related concepts of identity and culture that are central to explaining individual and group behaviour in organizational context (Irrmann, 2002: 164). The change initiative was initiated by management following a search and evaluation of the general business environment to see what other organizations were doing to improve their operations. There was no prior consultation with employees, nor were any attempts made to involve mine workers before implementing what management described as a more ‘scientific’ and ‘transparent’ system of employee performance management. As it turned out, this change disrupted operations, introduced new procedures that were scorned and fiercely resisted by miners, and served to increase levels of discontent and hostility among employees. One of the major threats that this new initiative posed for employees centred on the issue of identity. Violations to the norms and expectations of miners undermined the culture of the workplace and disrupted the social environment within which work took place. This resulted in heightened sensitivity, the generation of stories to make sense of what was going on and a series of reactions by employees to these identity threats. We examine these processes in our analyses of new empirical data and in so doing draw attention to the importance of workplace culture and the identity of miners in explaining employee behaviour in response to a managerially imposed change. We commence with a brief discussion of our key concepts, which is followed by an outline of our research strategy and methodology prior to presenting the main body of our argument.