Head and neck inflammatory pseudotumors (IPs) are rare, idiopathic, non-neoplastic lesions that most commonly affect the orbit, but may involve other areas such as the larynx, oropharynx, paranasal sinuses, and meninges. We report the case of a 55-year-old man who presented with progressive left-sided hearing loss, aural fullness, and otalgia. Computed tomography and magnetic resonance imaging (MRI) detected a soft-tissue mass in the left temporomandibular joint (TMJ). Histopathologic examination showed overlying squamous epithelium with hyperkeratosis, parakeratosis, subepithelial fibrosis, and chronic inflammatory infiltrate, which were consistent with an IP. Radiologic images and MRI indicated an ill-defined soft tissue involving the roof and posterior aspect of the TMJ, extending into the anterior external auditory canal. Our case was treated with a 2-week course of high dose prednisone (1 mg/kg) and a 2-week taper with resolution of symptoms. Two years after treatment, the patient shows no evidence of recurrence on MRI.