The topic of this case report is a rare subconjuctival osseous choristoma that corresponded to the left lateral sunconjunctiva and canthus. A 20-year-old man was asymptomatic when he arrived for the examination. His full ophthalmic examination was normal. Orbital computerized tomography was concordant with osseous lesion. Osseous choristomas are the rarest forms of ocular choristomas, they are usually being defined as sporadic, and they are found at the superior temporal region of the episclera. In our case, choristoma was in the lateral canthus of the left eye. We had administered surgical excision by reason of the patient's cosmetic requirement. We had noted that the lesion was adherent to conjunctiva but not to the sclera and the muscles. After surgical treatment, we saw mature heterotrophic osseous tissue in subconjunctival area and Haversian canals in compact bone tissue.