This paper reviews the educational dropout rate in e-learning system and its causes. Literature review indicates that the dropout rate in e-learning is more than traditional learning. This phenomenon is influenced by interaction between cultural, technological and psychological factors. In this case study, the considered variables include: gender, semester and entrance exam average in the Iran University of Science and Technology E-Learning Center. The results of this study indicate that male's dropout rate is statistically more than that of females. Educational dropout rate in the third and fifth semester is higher than other semesters but this result is not statistically significant. Descriptive statistic indicates that entrance exam QPA in persistent student is more than dropped student, but the difference between these averages is not significant.