The omnipresence of digital media in all parts of our daily life raises the question of how it can contribute to language learning. This research project focuses on the potential of asynchronous computer-mediated communication for cultural learning in the context of language learning. The study was conducted in the seminar on Landeskunde at Stockholm University which integrates language learning and content learning about the ‘culture’ of German-speaking countries. The concept of cultural learning that underlies this seminar rests upon a knowledge-based concept of culture: Language learners are supposed to acquire parts of the explicit and implicit knowledge that is shared by the speakers of the target language. In the context of language learning, asynchronous computer-mediated communication is mainly used for two reasons. First, it allows learners to reflect to a greater extent on the content and the language of their written contributions (in comparison to face-to-face-discussions). Second, it facilitates interaction between the learners which can result in the co-construction of knowledge. As there are no studies on cultural learning in asynchronous computer-mediated communication, this qualitative research is exploratory. The data consists of the written contributions in a discussion forum. Furthermore, students who participated in the discussions were interviewed about their experiences during the course. By describing features of the online-discussions (e.g. length of the written contributions) and factors that influence the activity of the students (e.g. task, teacher role, teaching context), the first part of the analysis constitutes the background for the second part of the analysis and shows that computer-mediated communication is a meaningful tool for content and language integrated learning because it supports language and content leaning. Different modes of task processing are identified in the second part of the analysis: Summary of facts, Reflection about terms and interpretations, Present-day relevance, Change of perspective and Narrative practices. Those modes are analysed with regard to their potential for cultural learning in asynchronous computer-mediated communication. The analysis shows that all modes have a potential for cultural learning but only contributions which contain Reflection about terms and interpretations and those which identify the Present-day relevance of historical events lead to interaction between the students. In summary, this study identifies factors that influence students’ actions in an asynchronous online discussion forum and the potential of their practices for cultural learning.