There has been considerable research into the technical aspects of virtual teams. By contrast, few studies have focused on their ‘human factors’, such as the way team members cooperate within the context of cross-national boundaries. This study applies a ‘mixed method’ approach to research virtual teams in three Asian economies: Indonesia, Taiwan and Vietnam. We find that critical human factors, including individual cultural intelligence, cultural openness and self-efficacy, significantly influence team member knowledge sharing willingness in cross-national virtual teams. However, a positive relationship between team member knowledge sharing willingness and knowledge sharing behaviour is not supported because other elements, such as interpersonal trust, leadership, team interaction and member language ability, can significantly affect the effect of the above mentioned factors on virtual team knowledge sharing. Our study offers a new model to improve the study of virtual teamwork and provides practical applications for managing cross-national teams, especially in the selection, training and development of team members.