An 8-year-old girl died suddenly without prior symptoms. Post-mortem examination identified both systemic group A streptococcal infection and hypertrophic cardiomyopathy. She had no history of cardiac symptoms and was not in a high-risk group for sudden death due to hypertrophic cardiomyopathy. We believe the disseminated but asymptomatic group A streptococcal infection precipitated her early death from hypertrophic cardiomyopathy. Sudden unexpected death during systemic infection should be followed by post-mortem examination to look for evidence of hypertrophic cardiomyopathy, as this diagnosis has genetic implications for other family members.