This study employs classic grounded theory methodology to produce a theory of rehumanising knowledge work through fluctuating support networks in the knowledge workplace. Data consisted of field notes and transcripts from personal interviews and focus groups. Participants were drawn from the public and private sectors and a variety of professional fields under the general rubric of knowledge work. Data were analysed using the full complement of procedures that comprise classic grounded theory methodology, including theoretical sensitivity, core emergence, constant comparison of empirical indicators to theoretical saturation and hand sorting of conceptual memos to achieve theoretical integration. The thesis explains the basic social structural process of fluctuating support networks through which knowledge workers self-organise to overcome dehumanised work environments, consequent of a rapidly changing workplace context. Such networks operate outside the formal organisation. They are epiphenomenal - self-emerging, self-organising, and self-sustaining. Participation is voluntary and intuitive. The core variable of the theory is the basic social psychological process of rehumanising. Through fluctuating support networks, knowledge workers rehumanise their work and work environments. Rehumanising gives meaning to work while sustaining energy and commitment. Rehumanising is characterised by authenticity, depth and meaning, recognition and respect, safety and healing and kindred sharing. Network relationships offer validation and support. Network members pursue shared interests and passions. Network activities are characterised by challenge, experimentation, creativity and learning, providing members with renewed energy and learning. The resultant sense of achievement builds confidence and passion for sustained network engagement. The contributions of the thesis to knowledge centre on the role of informal networks in the knowledge workplace and relate to theories of organisation, social networking, motivation and social learning. Knowledge of fluctuating support networks will enable managers to understand their functionality as psychological infrastructure for resolving workers’ concerns and needs in coping with change in the knowledge workplace