Based on the ethnographic data collected from the workplace of an academic library, I argue that workplace learning (WL) is a situated socio-cognitive process. It is expedited by knowledge management (KM), which is a collective effort to generate, share, and institutionalize work-related knowledge. KM is inherent in the face-to-face conversational interactions embedded in planned formal training, planned informal sharing, and spontaneous informal learning. When face-to-face interaction is not possible, KM is accomplished through textualization. It helps the members of the workplace acquire new work-related knowledge and integrate it to their common, contextualized knowledge base. The contents of the knowledge base are manifested in the members' professional practices and explicated by their professiona1!communal discourse. By virtue of their distinctive practices and discourse, the members form a community of practice (CoP) and gain their professional/communal identity. Whenever they engage in KM, perform their practices, and/or use their discourse, they authenticate their professional/communal identity and enact their CoP.