Ventriculitis commonly arises as a complication of various central nervous system conditions. The causes of ventriculitis include both iatrogenic conditions, such as catheter-related infections, and non-iatrogenic conditions, such as community-acquired bacterial meningitis. The incidence of pyogenic ventriculitis associated with community-acquired bacterial meningitis remains unclear. Additionally, the optimal treatment strategy for pyogenic ventriculitis secondary to community-acquired bacterial meningitis remains uncertain. A 47-year-old man presented with headache, fever, and impaired consciousness. At admission, cerebrospinal fluid analysis five days after the onset (day one) revealed elevated white blood cell count with neutrophilic predominance, increased protein levels, and significantly reduced glucose. Initial brain computed tomography (CT) showed bilateral lateral ventricular enlargement with subtle fluid accumulation in the right lateral ventricle. Despite the initiation of empirical antimicrobial therapy, follow-up CT two days later demonstrated a rapid progression of fluid accumulation in the bilateral lateral ventricles. Diffusion-weighted magnetic resonance imaging (MRI) confirmed high signal intensity within the ventricles, consistent with intraventricular pus. Emergency external ventricular drainage (EVD) was promptly performed, and cultures from the intraventricular pus identified