Florid cemento-osseous dyspl잃ia with concommitant traumatic bone cyst is uncommon condition. We report a case of florid cemento 。,sseous dysplasia involving four quadrants of the jaws and associated with large cystic lesion of the mandible misdiagnosed as a multiple odontogenic keratocysts in a 37-year-old Korean woman. Histological examination revealed unencapsulated fibroblastic proliferation with formation of bone and cementum, showing different developmental stages, and cys디c lesions resembling a traumatic bone cyst.