Dermoid cysts are malformations that are rarely seen in the oral cavity. An intraoral dermoid cyst grows slowly, but may enlarge and interfere with deglutition and speech, or can pose a critical risk to the airway and therefore require immediate surgical intervention. Dermoid cysts may develop above or below the mylohyoid muscle, causing a submental or submandibular swelling. Surgical excision is the treatment of choice and recurrence is rare. An intraoral approach for the treatment of large lesions presenting above the mylohyoid muscle provides good cosmetic and functional results. We report a case of a 26-year-old female who developed an epidermoid cyst presenting as a large sublingual swelling causing speech and swallowing difficulties. The lesion was surgically excised using an intraoral approach. Microscopic examination revealed a dermoid cyst of the epidermoid type. This case shows that dermoid cysts may be successfully diagnosed and managed using a series of simple yet effective clinical procedure.