It aims to describe how the course wiki was used to teach writing for academic and professional purposes, and to analyse what impact using the wiki had on the writer–reader relationship. The case study employed several research techniques, including participant observation, text analysis and a self-report questionnaire. The texts published by students on the wiki were examined for reader-oriented features and interactional metadiscourse resources. The results indicate that using the wiki for writing activities made students pay close attention to grammatical correctness and structural coherence.