Despite the inherent limitations imposed by working with an organism that still has a very limited genetic map and relatively few systems for manipulation of the genome, much has been learned in the past decade. Recent applications of the technology of monoclonal antibodies and recombinant DNA, coupled with careful studies of the immunobiology of pili and various outer membrane structures have provided exciting insights into the molecular pathogenesis of gonococcal infections. One of the principal lessons is the sophistication of the gonococcal strategies for evading the host defenses, including high-frequency variations of pili and P.II and an extracellular protease for specific cleavage of IgA1. It is unclear how much antigenic variation will limit vaccine development. Regardless, the pursuit of a vaccine has led to important new fundamental knowledge of the genetics and structure-function relationships of several cell surface components, and the future promises to be both rational and interesting.