Thyroglossal duct cyst (TGDC) is one of the most prevalent congenital midline cervical anomalies which commonly appear during childhood. It has a typically slow-growing presentation with small- or moderate-sized swelling. Here, we described our experience in managing a case of TGDC with an extraordinary clinical course and size, with further evidence from a literature review. A 35-year-old gentleman presented later in adult life with a large midline neck mass of 9.3 x 9.0 x 10.7 cm reaching up to the level of mandible superiorly and sternal notch inferiorly. His history and physical examination, along with fine needle aspiration cytology (FNAC) and CT scan, were suggestive of TGDC. He successfully underwent a Sistrunk operation for TGDC without any morbidity. Postoperatively, he recovered well without evidence of recurrence during follow-up. Large TGDC is always a challenge to clinicians. Correlating the clinical features and imaging is crucial to decide the appropriate surgical treatment.