Given that massive open online learning courses (MOOCs) are considerably different from traditional classrooms in terms of roles and responsibilities of instructors and learners, successful learners are required to be self-directed in MOOC learning environments. One of the most popular self-directed learning (SDL) models proposed by Garrison (Adult Education Quarterly 48(1):18-33, 1997) includes three components: motivation, self-monitoring, and self-management. This model was originally discussed from traditional online and face-to-face learning environment. Thus, the present study investigated the relationship among motivation, self-monitoring, and self-management in MOOCs by surveying 322 MOOC learners. Using structural equation modeling, this study found that motivation directly affected self-monitoring and indirectly influenced self-management through self-monitoring. In addition, self-monitoring positively influenced self-management. Therefore, promoting student self-monitoring skills and motivating students is critical. Additional research is needed on the ways to facilitate and support self-monitoring of MOOC learners. Future research could examine the influence of the three elements of SDL on learning achievement and engagement. In addition, further exploration of learner behaviors in MOOCs could provide insights on facilitating learners' SDL.