Epulis osteoplastica is a rare disease. We report a case of giant epulis osteoplastica containing a largesequestrum. A 63-year-old man was referred to our clinic because of a painless swelling on the left mandibularalveolus. Intraoral examination revealed an elastic hard tumor with a normal surface in the left lower molar region.Radiographic examination showed a large radiopaque mass separate from mandibular bone. Gingival tumor excisionwas performed with the patient under general anesthesia. The excised specimen measured 50 X 38 X 28mm and contained the bony mass. Histopathologically, the lesion was diagnosed as epulis osteoplastica with asequestrum. The patient was followed up for 4 years after the operation, without any recurrence.