The purpose: Is to assess the efficacy of enucleation process as an effective treatment modality in management of large sized (aggressive) cemento-ossifying fibroma (COF) or not.   patients and methods:  Six patients presented with a large expansile, painless growth in the maxilla, diagnosed a cemento-ossifying fibroma were included in this study. The surgical techniques of COFs which applied for six cases were the enucleation of the tumor masses with surgical removal of the sclerotic margins around the lesions.   Results:  Enucleation  process    was  curative  for  (aggressive)  large  sized  COF  lesions. The interesting points; the capsules of lesions were not violated and the sclerotic margins were tumor free. Conclusion: Enucleation with peripheral curettage is quite enough surgical intervention for management of large sized COFs. .