Group B streptococcus (GBS) is recognised as one of the leading organisms in early-onset neonatal sepsis but is also a cause of late-onset GBS septicaemia, meningitis and rarely, infective endocarditis (IE). We report a case of a healthy term neonate who developed GBS septicaemia and meningitis having presented with parental concern and poor feeding. Subsequent identification and treatment of GBS resulted in the requirement for long-line intravascular access in order to administer antibiotic therapy. One week later, after repeated parental concern and symptoms of shortness of breath, the neonate presented to Accident and Emergency and subsequently a Paediatric Cardiorespiratory Intensive Care Unit where emergency resuscitation procedures were required and diagnosis of severe IE affecting the mitral valve was made. Mitral valve replacement was complicated with significant morbidity and prolonged hospitalisation. An innovative procedure to insert a Melody valve was successful.