We report an adult case of pontine infarct complicated by a community-acquired pneumococcal ventriculitis. An 85-year-old woman was referred to the hospital with left-sided weakness and persistent fever despite antibiotics therapy. Diffusion weight magnetic resonance image revealed high signal intensity on the right paramedian pontine and the occipital horn of the lateral ventricle. In the cerebrospinal fluid (CSF) examination, white blood cell count was 2,720 /mm3, glucose level was 4 mg/dL (simultaneous blood glucose level was 135 mg/dL), and CSF protein level was 2,025.4 mg/dL. On admission day 4, CSF culture showed Streptococcus pneumoniae. Despite continuous antibiotics treatment, she expired on admission day 7. In patients with pneumococcal ventriculitis, despite high mortality as in this case, early detection and treatment improve clinical outcome. Also aggressive treatment (intraventricular antibiotics injection, and pus drainage) should be considered.