Approximately 70% of sudden sensorineural hearing loss (SSNHL) cases are idiopathic, but SSNHL may occasionally be related to fatality. Here, we report the case of a 54-year-old Asian female who complained of hearing loss as a primary symptom and was diagnosed with pyogenic ventriculitis (PV) derived from Streptococcus agalactiae endocarditis. Both PV and S. agalactiae endocarditis are rare and very severe infections with a high mortality rate. Rapid intensive treatment and surgery were required for successful clinical outcomes.