Using participant-observation and discourse analysis, this study explores the communication occurring on the Breast Cancer List, an on-line discussion group which continues to grow in membership and activity. Issues discussed include the evolution of the List, who participates, what topics are discussed. Three major dimensions are identified: exchange of information, social support, and personal empowerment. Social support via computer is compared with face-to-face groups. Empowerment centers on enhanced decision-making and preparation for new illness-related experiences. The influence of gender is considered in terms of communicative style and limitations of access. It is concluded that the List fulfills the functions of a community, with future concerns about information control and the potential to enhance patient-provider understanding.