The agility of the global IS project manager is considered to be important for the success of global IS projects. Yet, there has not been much research on the agility of the global IS project manager from a knowledge perspective. The objective of this research is to investigate the knowledge sets that influence the agility of a global IS project manager, and the mediation effect of the agility on project success. A sample of global IS project managers were surveyed to assess the knowledge that affect the agility of the project manager. System knowledge, project management knowledge, cultural knowledge and interpersonal knowledge had an impact on a project manager's agility. We have also found the mediation effect of the agility on global IS project success. The results have important practical implications as to what areas of knowledge organizations should focus to train their potential project managers for the project success.