Traditional approaches to knowledge collaboration and sharing have proven to be limited in the sense of addressing organizational needs of dynamic and distributed knowledge. More recently, the emergence of social media and the second generation of web technologies have introduced new ways and possibilities for sharing knowledge in organizations. In particular, the wiki technology, as one type of social media, is argued to mark a shift in the way people collaborate and share knowledge with each other on the web. It represents a new, open style of knowledge collaboration and sharing which allows anyone to freely and openly create and shape knowledge. In this respect, organizations have been attracted by this new dynamic approach which is based on open collaboration and flexible participation. More organizations are using wikis in order to effectively leverage distributed knowledge and improve their competitive edge. Against this backdrop, this research is concerned with examining how such organizations use social media, the wiki technology in particular, for sharing knowledge among individuals and groups. The aim is twofold: to develop an understanding of the ways by which these individuals and groups exchange and share knowledge with each other and to identify different factors that influence knowledge collaboration and sharing using a wiki in an organizational setting. The research is based on three published research papers which provide both theoretical and empirical accounts of knowledge collaboration and sharing using wikis. To these ends of this research, an interpretive case study was used as an empirical research method with interviews as primary sources of data. Several other data sources have been triangulated during the empirical inquiry including field visits, observations, and documents. The case took place at a large multinational organization that used a wiki as a collaborative platform to support knowledge sharing among members of several professional communities of practice. Eventually, the outcome of the research is a thorough understanding that describes knowledge collaboration and sharing using a wiki as a dynamic social process involving recursive and dynamic social interactions among members of communities of practice through which knowledge is collaboratively constructed and reconstructed and thus shared. It also presents a dual impact of wiki openness on knowledge collaboration and sharing within organizations.