True Cementoma or benign Cementoblstoma is a rare odontogenic tumor that represents less than 1% of all reported odontogenic tumors. it was first described as a benign tumour that forms cementum or cementum like tissue mass around the teeth roots and that the only true cemental neoplasms are benign cementoblastoma and cementifying fibroma.Its most common site is the posterior mandible mostly associated with molar and premolar teeth, and it rarely occurs in anterior teeth. It has a higher prevalence in male population and usually occurs before the third decade of life. the literature highlights that the treatment of choice for benign cementoblastoma is surgical removal of both the tumor and associated teeth. In this case report, a case of a 29-year-old male patient with a benign cementoblastoma (true cementoma) in the posterior mandible impeding the path of normal occlusion is presented. Whereby surgical removal of the mass and its histological examination was done to confirm its nature. Although it is a rare neoplasm constituting to less than 1% of benign odontogenic neoplasms, oral and maxillofacial surgeons should be aware of its diagnosis, clinical picture, histopathological features, treatment and prognosis as it may pose a risk to the patient's dentition and bony structures.