This report describes a 4-week-old female baby with disseminated group B streptococcus (GBS) infection. The illness began as a swelling with violaceous hue of perineum and lower abdomen, a manifestation that may be falsely attributed to a traumatic injury. GBS septicemia, meningitis and cellulitis of lower abdomen was confirmed by cultures. This case illustrated an unusual presentation of GBS infection as cellulitis of lower abdomen. The presence of concurrent septicemia and meningitis in this case indicated that a more extensive diagnostic work-up and a more aggressive therapeutic approach are needed for young infants with cellulitis.