This study examines factors related to student self-efficacy beliefs in on-line groupwork. Participants in this study were 204 graduate students taking an online graduate-level course from a public university in the Southeast United States of America. Two-level hierarchical linear models were used to examine predictors of the students' self-efficacy. Three student-level variables were found to be related to groupwork self-efficacy: individual's willingness to handle groupwork challenge, trust relationship, and leadership influence. At the group level, the group's willingness to handle groupwork challenge was positively related to individual student's groupwork self-efficacy. Discussions of the findings suggest that leadership is important for groupwork. Instructors of online courses are recommended to design high-quality group projects that are purposeful, meaningful, challenging, and engaging. Communications between group members are also recommended to build trust. Implications of the findings to online learning and instruction as well as directions for future research are presented.