<p>Since Taiwan's economy is dominated by small and medium-sized enterprises, the formation of virtual teams is even more important for Taiwanese companies due to the impact of COVID- 19. Hence, this study draws on the virtual team climate and the theory of planned behaviour (TPB). However, it also adds pluralistic ignorance (which stems from social cognitive bias arising from universal behavioural adherence to social norms) as a key inhibitor to explore factors affecting the quantity and quality of knowledge-sharing behaviour through knowledge management systems (KMS) in virtual teams. A field survey of 528 employees from 72 companies in Taiwan and working in virtual teams was analysed utilising partial least squares structural equation modelling (PLS-SEM) to evaluate the outcomes empirically. The findings show that the virtual team climate, perceived behavioural control, and subjective norm still positively affect knowledge-sharing behaviour. However, more surprisingly, the moderating effect of pluralistic ignorance dampens the positive relationships between (1) the intention to share knowledge and knowledge-sharing behaviour and (2) the virtual team climate and knowledge-sharing behaviour within virtual teams. Finally, in addition to the practical implications for managers of knowledge-intensive companies who are keen to adopt virtual teams, this study provides several theoretical and managerial implications for relevant managers and academic researchers.</p>