Group B streptococcus has emerged as a prominent neonatal pathogen in developed countries since the late 1960s. The incidence of disease remained fairly constant until the 1990 s, when prevention efforts increased. American consensus guidelines were endorsed in the mid 1990 s; since then a decrease in disease incidence has been reported in the United States. This review summarizes the main issues regarding the prevention of neonatal infection and presents aspects of group B streptococcal disease with the first population data recently obtained in a northern region of Italy.