A solitary brainstem abscess is a rare fatal intracranial infection, which can be mistaken for an acute stroke complicated with a systemic infection. Dental caries without abscess formation can be a possible source of infection. Herein, we describe the case of a 59-year-old man with dental caries who presented with a 4-day history of progressive dizziness, double vision, gait ataxia, emesis, and left facial and body numbness. Fever, suboccipital headache, and difficulties in urinating and defecating were noted on admission. Acute brainstem infarction and suspected aspiration pneumonia were then diagnosed. Magnetic resonance spectroscopy and diffusion-weighted imaging demonstrated a solitary pontine abscess. The neurologic deficits continued improvement after he completed 8 weeks of intravenous antibiotics. The successful nonsurgical treatment of the brainstem abscess in this case was based on high clinical suspicion, early diagnosis, and early combination of corticosteroids and broad spectrum antibiotics.