Streptococcus milleri is a known commensal of the female genitourinary tract, but its pathogenicity in neonates has been reported in only a few cases. During a period of one year in an obstetrical unit, Streptococcus milleri was isolated from nine neonates and from one foetus after a spontaneous abortion. In seven of the nine newborns, neonatal infection was assessed and Streptococcus milleri was the lone pathogen involved, associated with positive blood or vaginal cultures in four mothers. Because Streptococcus milleri requires special conditions for identification, it is probably underestimated as a cause of neonatal infection and septic abortion.