The course "Teaching Methods in Information Science" is designed for senior students at the Faculty of Arts and Sciences, University of Rijeka (Croatia) and is realized by a blended learning model or a combination of a face-to-face environment and online learning. This paper covers the topic of online discussion as one of the most significant learning activities in the context of this course. Among many tasks for teachers in an online course, moderating online discussion is one of the most demanding. It requires lots of teacher’s time, effort and skills. The paper describes tasks for teacher while moderating online discussions, as well as discussions initiated during the course.