Cementoblastoma or benign cementoblastoma is the only true benign neoplasm of cementum origin derived from ‘Mesenchyme or odontogenic ectomesenchyme, with or without odontogenic epithelium. The cementoblastoma is a relatively rare odontogenic neoplasm of the jaws comprises 1% to 6.2% of all odontogenic tumors. It is characterized as a large mass of cementum or cementum-like tissue attached to the roots of an erupted permanent tooth and very rarely being attached to the primary tooth. A 10-year old male patient came to the Dental Unit with the chief complaint of pain and swelling over lower left back tooth region since 2 months. The pain was a dull, not radiating and intermittent in nature. On examination, a small single, bony hard, non tender swelling was found in the mandibular first molar region with obliteration of the buccal vestibule. The teeth in the affected region were non-carious. The involved tooth was vital and non-tender. The remainder of the examination was within normal limits and oral hygiene was excellent. The extra oral radiographic examination revealed an approximately 1-1.5 cm radio-opaque mass attached to the mesial root of the primary left mandibular second molar and well demarcated by a radiolucent halo.