This research sought to investigate the relationships among self-leadership, social support and interpersonal competence of women engineering students. First, women undergraduate students' differences respecting self-leadership, social support and interpersonal competence were examined. Second, the relationships among self-leadership, social support and interpersonal competence were identified in terms of sub-factors of those three variables. Third, the effects of social support and interpersonal competence, as perceived by women undergraduate students, on self-leadership were explored. A total of 398 women undergraduate students from three universities in Korea responded to survey based on a three-variables scale. The findings were that, firstly, women engineering students scored lower in all of the three variables including self-leadership, social support and interpersonal competence, and that these major differences were statistically significant. Secondly, a positive correlation among self-leadership, social support and interpersonal competence was identified. Thirdly, it was determined that self-leadership was affected significantly by social support and interpersonal competence. The practical implications of these findings are discussed herein, with particular attention on education for promotion of self-leadership, social support and interpersonal competence.