We report a case of squamous cell carcinoma originated from a sacrococcygeal tailgut cyst in a 73-year-old female patient. Tailgut cysts are generally multilocal and have a layer of either columnar, squamous or transitional epithelium, or a combination of these. This case was treated with surgical excision and radiotherapy. Cancer presentation of a congenital abnormality in old age is a rare entity. This report is the first case of squamous cell carcinoma developing in a tailgut cyst without any synchronization, as an isolated (pure) pathology.