Cemento-Ossifying fibromas are rare fibro-osseous lesions that affect the jaw bones and are included in the group of mesodermal odontogenic tumours. Clinically, it is a large asymptomatic tumor of aggressive appearance. Four separate categories have been identified: Periapical cemental dysplasia, benign cementoblastoma, cementifying fibroma and a rare gigantiform variety. It has been suggested that the origin of these tumour is odontogenic or from periodontal ligament. This lesions commonly seen in women in 3rd and 4th decade of life. Usually in the jaw region the lesions are found mostly in the tooth bearing area. In this article, we present two cases of unusual presentation of Central Ossifying Fibroma involving lower border of mandible and its management.