Introduction: An earlier study of physicians' perceptions of interactive online learning showed that these were shaped both by program design and quality and the quality and quantity of interpersonal interaction. We explore instructor roles in enhancing online learning through interpersonal interaction and the learning theories that inform these. Methods: This was a qualitative study using focus groups and interviews. Using purposive sampling, 50 physicians were recruited based on their experience with interactive online CME and face-to-face CME. Qualitative thematic and interpretive analysis was used. Results: Two facilitation roles appeared key: creating a comfortable learning environment and enhancing the educational value of electronic discussions. Comfort developed gradually, and specific interventions like facilitating introductions and sharing experiences in a friendly, informative manner were helpful. As in facilitating effective small-group learning, instructors' thoughtful use of techniques that facilitated constructive interaction based on learner's needs and practice demands contributed to the educational value of interpersonal interactions. Discussion: Facilitators require enhanced skills to engage learners in meaningful interaction and to overcome the transactional distance of online learning. The use of learning theories, including behavioral, cognitive, social, humanistic, and constructivist, can strengthen the educational design and facilitation of online programs. Preparation for online facilitation should include instruction in the roles and techniques required and the theories that inform them.