Drawing on the concept of organisational behaviour, this research augments the concepts of social capital theory and organisational culture with one pioneering precursor and mediator, the sense of well-being, to develop an integrative understanding of the factors affecting individuals' knowledge-sharing behaviour within the more complex context of the virtual organisation of Taiwanese Non-governmental Organisations (NGOs). A field survey of 131 employees from the selected virtual organisation was analysed using Structural EquationModeling (SEM) to examine the outcomes empirically. Our research offers a persuasive body of evidence supporting the notion that increasing employees' sense of well-being can successfully form a bridge that can connect social capital tendency, organisational culture and employees' knowledge-sharing behaviour. Surprisingly, and contrary to common belief, the integrated model shows that social capital tendency seems to play a more important role than organisational culture in affecting employees' sense of well-being within the virtual organisation in a Chinese cultural context. Consequently, this research reveals the subtle interplay of employees' sense of well-being, social capital tendency, organisational culture and knowledge-sharing behaviour, while the in-depth analysis provides strong support for knowledge management research and practice.