Purpose: This empirical paper aims to assess how social media can foster workplace learning within a globally dispersed project environment. In general, there are few studies on the use of social media in organizations, and many of these emphasize on issues related to knowledge transfer. Although learning traditionally has been as acquisition of knowledge, increasingly researchers point to learning-as-participation occurring through work collaboration. Social media promise increased opportunities for communication and collaboration, extending the context of collaboration beyond the local setting. However, there exists limited research on how social media can foster workplace learning, for example, between globally dispersed colleagues. Design/methodology/approach: The study is based on an exploratory, in-depth single case study of an international professional service firm's implementation of an internal wiki system to address the research question: how are social media utilized in an organization to foster workplace learning among its dispersed individual experts? Data are gathered in 35 semi-structured interviews, as well as documents studies and observations. Data are coded and analyzed utilizing the context and learning factors of workplace learning. Findings: The paper shows how the wiki system enables hybrid knowledge management strategies linked to virtual collaboration on daily project tasks, involving documentation, search, interaction and knowledge exchange, as well as socialization and learning from practice among dispersed groups and individuals. The learning mechanisms involved in virtual collaboration do not differ much from what is reported on face-to-face workplace learning, however, the context factors are extended beyond the local setting. Practical implications: The findings identify four determinants for using the wiki that can be of use to other organizations implementing similar virtual collaboration technology. First, the wiki must directly relate to the daily work by offering interactive and updated information concerning current project challenges. Second, the system must enable transparency in the daily project work to allow search. Third, the intention with the search is of lesser degree to identify encyclopedic information than it is to visualize individual competence. Fourth, the quality assurance of the data posted at the wiki is important. Originality/value: The study reveals how an international knowledge-based organization can utilize social media to leverage knowledge and experiences from multiple geographically dispersed projects by enabling virtual collaboration. Extant empirical research on workplace learning emphasizes on face-to-face interactions in groups, for example, when engineers, or accountants, in teams interact and collaborate at client premises. However, there exists limited knowledge concerning how workplace learning can be achieved through virtual collaboration.