Masked mastoiditis (MM) is a rare and diagnostically challenging condition characterized by inflammation of the mastoid air-cell system with minimal or absent otologic symptoms. Neurological manifestations are uncommon and typically associated with intracranial complications. We report the case of a 4-year-old boy presenting with a 6-day history of progressively worsening isolated motor tics, including head extension, frequent blinking, and repetitive squatting movements. There were no signs of infection, and otoscopic examination was unremarkable. Laboratory findings were within normal limits. Computed tomography revealed inflammatory changes within the mastoid process with bony erosion, while magnetic resonance imaging demonstrated a petrous pyramid abscess, meningeal irritation, and suspected sigmoid sinus thrombosis. The patient was treated with intravenous antibiotics followed by mastoidectomy. Postoperatively, the motor tics resolved completely, and no recurrence was observed during 15 months of follow-up. Masked mastoiditis in pediatric patients may present with highly atypical and non-specific symptoms, including isolated neurological manifestations. This case highlights that normal otoscopic findings do not exclude significant underlying mastoid pathology. Imaging studies, particularly CT and MRI, are essential for accurate diagnosis. Clinicians should maintain a high index of suspicion in children presenting with unexplained movement disorders. Early recognition and appropriate surgical intervention can lead to complete resolution of symptoms and prevent potentially life-threatening complications.