Purpose: The purpose of this study is to investigate the influences of system and instructor factors on e-learning effectiveness under the interactions of computer self-efficacy. In this study, the factors of the e-learning system are functionality, interaction, and response. The factors of the e-learning instructor are attitude, technical skills, and instructional method. The moderating effects of learners' computer self-efficacy are examined. Design/methodology/approach: The study surveyed general employees in the financial services industry in Taiwan. A questionnaire was developed to measure participants' perceptions. Four hundred questionnaires were sent out, and 362 were returned. Of these, 314 were valid, leading to a return rate of 78.5 percent. Findings: The results of data analysis indicate that both system and instructor factors have significant positive influences on e-learning effectiveness. Learners' computer self-efficacy has a moderating effect on the relationship between system functionality and training effectiveness. The higher the computer self-efficacy, the stronger is the relationship between functionality and effectiveness, and vice versa. However, computer self-efficacy does not have a significant moderating effect on the relationship between other independent variables and training effectiveness. Originality/value: Since both system and instructor factors have positive influences on e-learning effectiveness, HRD managers need to pay more attention to issues in both areas. High computer self-efficacy can result in better training effectiveness; therefore, it is necessary to pay attention to enhancing employee computer skills and their confidence in using e-learning. (Contains 5 tables and 1 figure.)