In the context of the European Commission's Communication published in response to the European Citizens' Initiative "Stop Vivisection", Action 1 aimed to conduct an assessment of current technologies, information sources and networks from all relevant sectors with potential impact on the advancement of the refinement, reduction and replacement of animals used for scientific purposes (the "Three Rs"). The main objective of this study is to map knowledge sources relevant to the Three Rs, to examine how knowledge is being shared, and to identify possible gaps and opportunities to enhance knowledge sharing. An inventory of knowledge sources (KS) potentially relevant to the Three Rs used in the area of life sciences has been compiled which should be viewed as a snapshot of the current status of knowledge sources available (the supply), and as a starting point for further analysis of knowledge sharing strategies. A public survey was also conducted to complement this study (supply versus demand), and to inform on how to proceed effectively with any knowledge management strategy. The survey has revealed that many involved in this area consider that whilst access to relevant knowledge sources is adequate, there is a need for better coordination of the sources, as well as for the communication of information. Opportunities for face-to-face exchanges are highly valued and there is a firm call for more developments in education and training at professional, university and secondary school levels.