Group B streptococcal (GBS) infection is one of the leading causes of neonatal sepsis worldwide. Despite a significant decline in early-onset (EOS) sepsis due to intrapartum antibiotic prophylaxis, the incidence of late-onset (LOS) infection has remained unchanged. However, LOS GBS sepsis affecting twins is very rare. We report on preterm twins born at 29 weeks of gestation: Twin B was 31 days old when he developed LOS GBS sepsis and meningitis, and Twin A was 35 days old when he developed LOS GBS sepsis. Tests for maternal GBS colonization in breast milk were negative. Both babies were treated with antibiotics and eventually discharged without complications.