The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process.

DM: Digastric muscle; EAC: External auditory canal; IOM: Obliquus capitis inferior muscle; LEM: levator scapulae muscle; MP: mastoid process; SOM: Obliquus capitis superior muscle.