In recent years viridans streptococcus has emerged as a new and significant cause of neonatal septicemia. This article reports our experience over a 6-year period with respect to the prevalence and clinical presentation of viridans streptococcal vis-a-vis Group B streptococcal septicemia in neonates. Viridans streptococcus was the organism most frequently isolated taking into account all positive blood cultures for streptococci in newborns. Although some similarities were observed between the two groups, viridans streptococcal septicemia was associated with a later onset of symptoms and with a lower incidence of respiratory distress and leukopenia. Clinical findings suggest that viridans streptococcus is a less virulent organism than is Group B streptococcus. The viridans streptococcus should be considered a pathogen in the sick neonate.