Increasingly more IS projects are globally dispersed. As a result, the success of IS projects can be affected by various global boundaries such as geographical distance, time separation, organizational boundaries and cultural differences. At the same time, system requirements dynamism significantly undermines global IS project performance because it is difficult for global teams to effectively sense and respond to changing system requirements. Therefore, to deliver quality systems on time and within budget in today's dynamic, global environments, process, people, and technology employed by IS projects need to simultaneously exhibit ambidexterity?i.e., both rigor and agility. Drawing upon prior literature and interview data from field studies, this research develops a theoretical model that explains and predicts global IS project success based on ambidextrous project capabilities. Specifically, the model identifies IS project rigor and IS project agility as two key IS project capabilities that moderate the negative effects of global boundary complexity and system requirements dynamism on global IS project success.