Infections of the upper respiratory tract and skin due to group A Streptococcus are common, and the organism is highly transmissible. In industrialized countries and to some extent in developing countries, control efforts continue to emphasize that group A streptococcal pharyngitis should be properly diagnosed and appropriately treated. In developing countries and in indigenous populations where the burden of group A streptococcal diseases appears greatest, the epidemiology is less completely defined and may differ from that in industrialized countries. There is a need for accurately collected epidemiological data from developing countries, which may also further clarify the pathogenesis of group A streptococcal infections and their sequelae. While proper treatment of group A streptococcal pharyngitis continues to be essential in all populations, it may be appropriate in developing countries to consider additional strategies to reduce rates of pyoderma.