Background: This study evaluates otitis media in prehistoric populations in northern Chile.Aims/objectives: Determining prevalence of otitis media and diagnostic usefulness of temporal-bone X-rays in skulls.Materials and methods: 444 skulls belonging to three groups: prehistoric-coastal (400-1000 AD), prehistoric-highland (400-1000 AD) and Pisagua-Regional Developments (1000-1450 AD). Skulls were evaluated visually and with Schuller's view X-rays. Five skulls diagnosed as having had otitis media, five diagnosed as normal, and one with temporal bone fistula also had a computed tomography (CT).Results: Changes suggestive of otitis media were present in Prehistoric-coastal 53.57%; Pisagua-Regional Developments 70.73%; prehistoric-highlands 47.90%. Diagnostic effectiveness of Schuller's view X-rays for assesing middle ear disease was confirmed by CT studies. The case with temporal bone fistula had changes suggestive of mastoiditis and possible post auricular abscess.Conclusions: There was a high prevalence of otitis media in prehistoric populations in Chile. The higher prevalence in one group was presumably due to racial factors. Temporal-bone X-rays are effective for massive evaluation of ear disease in skulls. A case of mastoiditis with temporal bone fistula and possible post-auricular abscess is documented.Significance: Documenting racial factors in otitis media. Validating X-rays for massive evaluation of otitis media in skulls.