Common wisdom in the literature on virtual team is that rigid, explicit and formal forms of coordination are required for the integration of different expertise to take place, while tacit forms of coordination are difficult to establish and maintain. This study challenges this claim and evaluates the contribution of virtual team common knowledge – a tacit coordination mechanism – on virtual teams’ knowledge integration effectiveness. In an attempt to reconcile the different theoretical stances adopted in previous studies, we offer a new conceptualization for “virtual team common knowledge” and assess its structural and psychometric properties. A measure is developed and tested with 700 individuals spread across 102 virtual teams in the field. The evidence suggests that virtual team common knowledge is formed by common task knowledge, common expertise knowledge, common IT interaction knowledge, and common specialized knowledge. Virtual team common knowledge is also found to positively influence knowledge integration effectiveness.