The convening of the 3rd International Workshop on Monoclonal Antibodies and Breast Cancer had the character of a self-search exercise. After almost a decade of research in the basic and applied aspects of the use of serological means to diagnose and possibly treat breast cancer several milestones have been reached. Among them a clear understanding of immunopathological use and limitations of monoclonal antibodies against breast epithelium, the complete development and clinical use of immunoassays for circulating breast epithelial antigens, the striking advances in the diagnostic use of monoclonal antibodies to estrogen and progesterone receptor proteins and the first communications on proposed immunotherapeutic use of different conjugates of anti-breast antibodies. New areas of investigation have developed in our field, some which are reaching a full blossom while others are still facing obstacles and at times a re-definition of their goals and objectives. These meetings have acted in a way as a clearing house and have permitted their attendees to derive predictions that have helped shape future research and fine-tune objectives. But above all, the re-evaluation of past research at these Workshops and the renewed excitement brought to them by new information has helped generate a momentum and enthusiasm that assures for the future large scientific gains.