Computer-Mediated Communication (CMC) is used in different contexts such as business, non-profit organizations, and education and uses different tools such as computer conferencing, e-mail, and groupware. However, it is apparent that the field of CMC lacks established methodologies to analyze the phenomena. This article introduces the use of Formal Concept Analysis (FCA) as a methodology to visualize the data in CMC. FCA is based on a mathematical lattice theory and offers visual maps (graphs) with conceptual hierarchies. Combined with content analysis, FCA is proposed to be a potential method for the analysis of CMC. In this study, three categories (social, cognitive, and metacognitive) from Henri's (1992) model for CMC content analysis were applied to FCA after a previous study used a contentanalysis method based on Henri's model to convert the data from a computer conference. The purpose of this article is to provide an example of the application of FCA to CMC and to argue for its potential use for analyzing on-line discourse. Although this article specifically addresses issues related to analyzing data in CMC for education, the methodology is applicable to the analysis of CMC for different purposes.