Purpose: Online learning and the use of technology-based learning management systems (LMS) are on the rise in higher education. The purpose of this study is to explore how the frequent use of these LMS mediates the relationship between three types of learner interactions and student outcomes. Design/methodology/approach: This was an exploratory study using surveys that collected information on students' use of LMS, their interactions and student outcomes. The participants of this study consisted of 362 undergraduate students from a South Korean University who were taking online classes as part of their degree. Findings: The findings support existing research that increased learner interactions have positive effects on learning outcomes. However, some of the positive effects were reduced when considering the effect of higher levels of LMS use. In particular, learner-to-learner interactions. Research limitations/implications: This information will enable educators to identify, measure and evaluate their online courses and consider how to integrate LMS use effectively. Results imply that focus may need to be on how learner to learner interactions can be best supported through the application of LMS. Practical implications: This information will enable educators to identify, measure and evaluate their online courses and consider how to integrate LMS use effectively. Social implications: Learner-to-learner interaction through social networking platforms may be more beneficial in socially constructing knowledge than formalizing interaction through LMS. Originality/value: This study contributes to the field of online learning by suggesting that the importance of some types of learner interactions may be overestimated in relation to the importance of LMS use.