Necrotizing fasciitis (NF) is a severe soft tissue infection, characterized by rapid and fulminant progression. Thus, early suspicion, and prompt medical and aggressive surgical management are important for the clinical outcomes of NF. Despite the rarity of NF in infants and group B streptococcus as its cause, a 2-month-old preterm girl presented with NF involving the suprapubic, inguinal, and lower lateral abdominal regions caused by group B streptococcus. The girl recovered after early medical and surgical management.