A radicular cyst is a slowly-growing epithelial sac lining a pathologic cavity in the bone at the apex of a tooth. Large radicular cyst revealed by radiographic examination almost always appear to involved several teeth. The author observed a 31 year old woman with a labial swelling and palatal mucosal expansion of the maxillary anterior region. Radiographic examination indicated that the lesion extended from the left maxillary lateral incisor to the right lateral incisor. Cyst consisted of tan to gray yellow slightly firm to partly hard plaque like tissue measuring 3.4 x 2.2 x 0.3㎝. The author has treated the cyst by means of enucleation with apicoecomies of the involved teeth except the right central incisor. Recovery proceed satisfactorily and there were no clinical or radiologic signs of recurrence 8 months later.