Actinomycosis is a chronic purulent granulomatous disease caused by actinomyces, especially, actinomycosis of the tympanomastoid region is very rare.
A 14-year-old man presented with a complaint of persistent discharge from the right ear, and the diagnosis of actinomycosis was made during surgery because of a yellow-green mass throughout the mastoid and actinomyces with characteristic “Sulfur granules”.