As work teams have increasingly become the cornerstone of the post bureaucratic organization, there have been calls for a greater understanding of collective thought and action. Such understanding is deemed important for the design and management of teamwork. Theory suggests that feelings of ownership manifest themselves at the collective level, and positively affect team performance effectiveness. This study illuminates the role played by teamwork complexity and team self-management in the emergence of the psychological processes that are associated with the manifestation of job-focused collective psychological ownership (CPO). In addition, employment of serial mediation suggests that both teamwork dimensions put employees on two routes (intimate knowing of and the collective investment of the team members' selves into the job) that lead to the emergence of a collective sense of ownership, and together these two route variables and CPO sequentially mediated a positive relationship between teamwork design and team performance effectiveness.