Through literature review, this paper examines six empirical studies. Three cases are from the United States and the other three are from studies conducted in Asian. The purpose of this study is to identify whether or not self-directed learning is a key factor leading to successful academic performance in web-based learning environments. The in-depth analysis and discussion of each study finds that the effect of self-directed learning on academic success in web-based environments is divergent among six case studies. Follow-up studies should exclude potential problems identified in this paper.