This is a study based on the proceedings of a workshop concerned with extracellular virulence factors of mucoid strains of Pseudomonas aeruginosa in relation to Cystic Fibrosis. It is intended to further the understanding of mucoid P. aeruginosa infections and to provide benefit to those who need it most - the children and adults suffering from CF. It focuses on alginate as an extracellular virulence factor of P.aeruginosa in CF pulmonary infections and presents advances in the biochemistry and molecular genetics of alginate biosynthesis and the basic defect in CF and isolation of the gene. The non-mucoid to mucoid transformation in vitro and in vivo are discussed in relation to host responses to alginate. The structure, properties, and biosynthesis including genetics of alginate are dealt with in detail and related to its chemical physical and biological properties.