Title: Osseous Metaplasia Leading to Traction Retinal Detachment in the nonphthisical eye of Young Boy with Cytomegalovirus Retinitis. Purpose: To report a case of intraocular bone formation in an 11-year-old boy with a history cytomegalovirus (CMV) retinitis secondary to immunosuppression following Bone Marrow Transplantation due to hyper Immunoglobulin G (IgG) syndrome. Methods: An 11-year-old male presented with decreased vision in his better seeing eye. Clinical examination and Bscan ultrasound discovered a tractional retinal detachment with a large subretinal lesion. The patient was taken for surgical intervention. Results: The subretinal lesion was removed during surgery, and histopathologic evaluation revealed mature lamellar bone. Conclusion: This case shows that mature intraocular bone can be associated with tractional retinal detachment in a nonphthisical eye.