Cultural factors are often identified as a crucial influence on the success or failure of information systems in general and computer-mediated communication (CMC) in particular. This paper goes one step beyond management measures and asks whether there is a theoretical foundation on which one can base the mutual influence of culture and CMC. The paper suggests a Habermasian approach to culture which sees a universal background to particular cultures in the structure of communication which creates and sustains culture. It provides an outlook on how such a Habermasian theory of culture can enable designers and users of CMC to reflect on their activity and improve the quality and reach of CMC.