<p>Parathyroid cysts are rare lesions, representing a very small fraction of pediatric cervical masses, and are often misdiagnosed as more common congenital neck cysts. Non-functional variants are particularly challenging due to the absence of biochemical abnormalities. Pediatric cases remain exceptionally uncommon, and preoperative diagnosis is rarely achieved. We report an 11-year-old boy with a six-month history of a painless midline cervical mass. Ultrasonography revealed a well-defined hypoechoic cystic lesion, and MRI demonstrated a 20 × 16 × 17&#xa0;mm thin-walled cyst inferior to the left thyroid lobe with mild tracheal deviation. Laboratory evaluation showed normal calcium and parathyroid hormone (PTH) levels, consistent with a non-functional lesion. Cyst-fluid PTH measurement was not performed. Because imaging could not conclusively determine the origin, surgical excision was undertaken. Intraoperatively, a well-encapsulated cyst adjacent to the inferior thyroid pole was removed en bloc. Histopathology confirmed a non-functional parathyroid cyst. Postoperative recovery was uneventful, and no recurrence was observed on follow-up. Review of pediatric cases reveals that most parathyroid cysts are non-functional and present as asymptomatic cervical swellings, frequently mimicking thyroglossal duct or branchial cleft cysts. Diagnostic confirmation often relies on cyst-fluid PTH analysis; however, as in our case, imaging and histopathology may be required when aspiration is not feasible. Surgical excision remains the most common and definitive management strategy in children, with consistently excellent outcomes. This case highlights the diagnostic challenges of non-functional parathyroid cysts in children and emphasizes the importance of considering parathyroid origin in persistent cervical cystic lesions. Early surgical excision provides both definitive diagnosis and cure.</p>