Luc's abscess is an exceedingly rare complication of otitis media, where the middle ear infection spreads extratemporally causing a subperiosteal collection under the temporalis muscle. It is known as a benign complication of otitis media as it is thought not to involve the mastoid bone in comparison to other types of extratemporal abscesses related to otitis media. We describe a challenging case of a 19-year-old male with Down syndrome diagnosed with Luc's abscess involving the mastoid bone. A high-resolution computed tomography scan is important to determine the extent of the abscess, with or without mastoid involvement, and the presence of complications. These findings will then help to determine the surgical options. Drainage of abscesses is a simple, initial, and conservative approach but less effective compared to mastoidectomy. 'Mastoidsparing' approach should only be considered if there is complete resolution after a simple drainage and antibiotic treatment.