The meeting on "Microbial Surface Components and Toxins in Relation to Pathogenesis" was held on May 15-19, 1989, in the Mitzpe Rachel guesthouse of Kibbutz Ramat Rachel in Israel. Four major topics formed the basis for the meeting: adhesion and colonization; cell invasion and intracellular multipli- cation; evasion of host defenses; toxins and systemic effects. The presentations clearly show that our understanding of the pathology, pathogenesis and bacteria-host cell inter-action has greatly advanced over the last few years. The contributions to our knowledge on the biogenesis of adhesins and their molecular organization, as well as on the mechanism of adherence to infected target tissue by pathogenic bacteria, have been particularly impressive. significant progress has been made in defining the nature of pathogenic and cytotoxic factors produced by bacteria, and much has been learned about the biochemical and antigenic modifications occurring in diverse types of host cells upon infection. The discussions of poly- saccharide capsules, bacterial endotoxins and secreted toxins illustrated the challenge and the possibilities for vaccine development.