Purpose: To describe the clinical course and management of a retained posterior segment cilium following open-globe injury. Methods: A single case was reviewed. Results: A high-velocity zone 1 open-globe injury was complicated by a posterior segment cilium detected on ultra-widefield imaging 3 months after trauma. The patient was followed with serial examinations and imaging during a corticosteroid taper. The cilium remained stable and clinically silent, with no evidence of vitritis, traction, or visual decline. Corticosteroids were gradually discontinued. After more than 1 year off steroids, visual acuity remained preserved, and no inflammatory sequelae were observed. Conclusions: Selected cases of retained posterior segment cilia may be managed conservatively when asymptomatic and without inflammatory or tractional complications. Ultra-widefield imaging facilitates delayed detection, and ocular immune privilege should be considered when weighing the risks and benefits of surgical removal.