Epidermoid cyst of the submental region is a rare disease. This is a kind of dysontogenetic eyst which developed from a misplaced fetal inclusion. Dysontogenetic cyst can be classified into epidermoid, dermoid and teratoid cyst. Recently, the authors experienced 3 cases of epidermoid cysts in the submental region. Case 1 : Patient is 29-year-old female who has had noticed painless growing mass in the mouth floor for several years. A protruded smooth and soft mass could be palpated in the sublingual and submental region simultaneously. It was easily removed and was about 6.0×3.5×3.0cm sized cyst which contained cheeze like material. Case 2 : 35-year-old male has had similar mass as case 1 for 15 years, which was associated with speech and swallowing difficulty. The local finding was similar to case 1 and it was also easily removed. Its size was about 6.0×5.0×5.0cm and also contained cheeze like material in it. Case 3 : 25-year-old male had soft cystic mass which was palpable in left sublingual and submental region simultaneously. It was also easily removed and was about 8.0×5.0×4.0cm sized cyst which contained cheeze like material. All of the 3 cases were completely cured by surgical removal without recurrence and were diagnosed as epidermoid cyst by the histopathological finding.