We report a case of acute sinusitis with intracranial complications in a 15-year-old man who presented with fever, headache and swelling of the left eyelid. Computed tomography (CT) revealed opacities in the left maxillary, ethmoid, and frontal sinuses, and low-density convex opacities in the left frontal epidural region. Magnetic resonance imaging (MRI) revealed an iso-signal intensity on T1-weighted images and an iso- to high signal intensity on T2-weighted images in the left frontal epidural region. Enhanced MRI revealed enhancement of the dura, and we made the diagnosis of epidural abscess. Cerebrospinal fluid examination was performed, and the findings led to the diagnosis of bacterial meningitis. Staining of the cerebrospinal fluid revealed gram-positive cocci. We performed emergent trans-nasal endoscopic sinus surgery and started the patient on antibiotic therapy. The antibiotic therapy was continued for a total of about 3 weeks, and the patient improved without sequelae. Early diagnosis and treatment are very important, because intracranial complications of acute sinusitis may result in neurologic sequelae and could even be fatal.