This thesis explores the issue of knowledge sharing in two knowledge-intensive organisations. It aimed to answer how individuals in knowledge intensive firms (KIFs) understand and enact knowledge - sharing networks within their departments, what enablers and barriers they encounter and, how the context of these organisations contributes to these understandings. The organisations were located in Mexico, which is portrayed by research as a country with specific cultural characteristics that could encourage bureaucratic structures, and one in which there is little existing research on the matter. Knowledge sharing research that has an organizational learning perspective acknowledges the complexities of knowledge sharing, regards it as a social process and questions the manageability of knowledge. This research resonates with that perspective and highlights the experiences and understandings of knowledge sharing amongst network actors in the organisation. It addresses a gap in the literature by exploring the role of the organisational context in shaping these understandings, mainly through organisational structure, while being shaped by them as well. In order to access these understandings, in-depth interviews were carried out with employees in five departments in the participating KIFs. Standardized open-ended interviews were carried out to obtain data about the patterns of knowledge sharing interactions in the knowledge-sharing networks of each department. Elements of a bureaucratic structure and culture in both organisations were found to deter knowledge sharing. These were reflected in the patterns of knowledge sharing of the networks examined. Also, an organisational discourse in Organisation X and a focus on accountability in Organisation Y appeared as influential in the understandings and enactment of knowledge sharing by actors. The findings of this research contribute to the growing literature that argues for more emphasis on the nurturing of organizational contexts that encourage social interaction and knowledge processes within it; a non-threatening environment and work arrangements that promote collaboration and learning through knowledge sharing.