Brain abscesses represent areas of localised infection of the brain parenchyma. Those confined to the brainstem are rare and usually fatal if untreated. Streptococcus intermedius is a common causative organism of brain abscesses and is associated with significant morbidity. We describe a case report of medullary abscess secondary to dental infection in a 68-year-old patient. The patient presented with headaches and flu-like symptoms progressing to left hemiparesis and reduced consciousness/bulbar function. The patient underwent emergency posterior fossa craniectomy and drainage with subsequent medical management with antibiotics. Prompt diagnosis, early surgical intervention and maximal therapy with antibiotics alongside extensive rehabilitation are all vital to ensure good neurological outcome. It is imperative for medical practitioners to consider the diagnosis of brain abscess in patients presenting with rapid onset neurological deterioration. Such cases require early neurological imaging with involvement of tertiary neurosurgery services.