Based on a study conducted in a core module of the Postgraduate Diploma in Education programme at the National Institute of Education (Singapore), this paper provides an account of the perceptions and experiences of pre-service teachers on the roles of their tutors in the online discussion board. The research methods included a questionnaire survey, two focus group interviews and an analysis of the discussion records. The findings suggest that there are gaps between the experiences and perceptions of the pre-service teachers on the roles of their tutors. These identified gaps have various implications for the role of the online tutor in practice: setting meaningful tasks; guiding participants in the 'technicalities' of online discussion; participating actively in discussions by answering queries, providing feedback and posing conflicting views to elicit thinking/reflection; keeping the discussion focused; drawing conclusions and providing content expertise; and recommending resources for extension of learning. Copyright © 2003 Taylor & Francis.