Pure infratentorial subdural empyema is a rare occurrence. Development of clinical triad of fever, vomiting, and headache in cases of chronic suppurative otitis media (CSOM) suggest the intracranial spread of infective pathology. As this clinical triad is a harbinger of pyogenic meningitis, diagnostic cerebrospinal fluid studies are undertaken. Contrast CT scan should precede such a diagnostic test. As SDE along the tentorial surface may remain undetected in axial sections of CT scans, a lumbar puncture may precipitate fatal tonsillar herniation ¹⁾