Streptococcus agalactiae causes approximately 160,000 cases of urinary tract infection (UTI) in the United States annually. These infections present in various forms, including acute cystitis and pyelonephritis, as well as asymptomatic bacteriuria (ABU). The host-pathogen interactions that occur during S. agalactiae UTI and mechanisms of pathogenesis are increasingly being defined based on in vitro and in vivo models of human infection, in addition to clinical case studies. In this presentation, I will provide an overview of these infections, including mechanisms of disease pathogenesis that stem from the interactions between bladder tissue and S. agalactiae. The dynamics of infection-induced cytotoxicity in human bladder cells, and the contributions of streptococcal virulence factors, including β-hemolysin/cytolysin (β-H/C), capsular polysaccharide, protein adhesins, and the global virulence regulator CovR, will be discussed. The biology of ABU-causing S. agalactiae strains, including how these bacteria might colonize the urinary tract by exploiting metabolic pathways that are novel for bacterial disease pathogenesis will also be discussed.