This chapter focuses on the complications of ear disease. The complications of otitis media (OM) often present acutely, but there will usually be either a background of recurrent acute otitis media (AOM) or of long-standing aural discharge and/or hearing loss. This chapter discusses the complications of OM, presentation, and the management principles. Disease spread occurs through three routes—direct extension, thrombophlebitis, and hematogenous dissemination. Fever, postauricular swelling, facial nerve paralysis, vertigo, etc. are signs or symptoms are suggestive of extracranial complications. Extracranial complications include mastoiditis/postaural abscess, labyrinthine fistula, labyrinthitis, petrositis and facial nerve palsy. Intracranial complications include meningitis, extradural/subdural abscess, brain abscess, sigmoid sinus thrombosis, otitic hydrocephalus and cerebrospinal fluid (CSF) leak. Otitic hydrocephalus occurs as a result of increased intracranial pressure secondary to middle ear infection. Symptoms can include headache, drowsiness, vomiting, blurring of vision, and diplopia. A CSF leak secondary to OM is due to an abnormal communication of the subarachnoid space with middle ear space/mastoid bone. Treatment depends on the clinical setting. Investigations and treatment of ear disease are covered in this chapter.