Septic rupture of the common carotid artery following total thyroidectomy may rapidly lead to exsanguination. We present a case report of a 16-year-old girl, diagnosed with a questionable thyroglossal duct cyst. Following the initial operative intervention with local excision of the cyst including resection of the medial part of the hyoid bone, pathology revealed papillary carcinoma. Thus secondary total thyroidectomy with locoregional lymphadenectomy was performed. One week later, a wound infection developed, necessitating lavage and drainage. On the 8th postoperative day, a dramatic bleeding of the right common carotid artery occurred. To our knowledge, this is the first reported case in the literature with a septic bleeding of the common carotid artery following total thyroidectomy after one week.