The indigenous populations of the Arctic are prone to middle ear infections starting with an early age first episode, followed by frequent episodes of acute otitis media (AOM) during childhood. A high proportion develop chronic otitis media. Acute mastoiditis is a serious complication of AOM in childhood with postauricular swelling, erythema, and tenderness, protrusion of the auricle, high fever and general malaise. The disease may protrude intracranially. The incidence rates for acute mastoiditis in the Western world range from 1.2 to 4.2 cases/100 000 per year. There exists no epidemiological data on acute mastoiditis in the Arctic region.