We report a case of intraocular cilium after micro-incision vitrectomy surgery for retinal detachment. A 61-year-old male underwent vitrectomy with cataract surgery for rhegmatogenous retinal detachment. The postoperative course was generally good with no re-detachment, but on examination 3 months later, a cilium was observed on the retina above the fundus. After discussing with the patient, it was decided to take no immediate action and just continuously monitor the patient in order to detect if there was worsening of any of the symptoms. The present case report suggests that foreign bodies such as cilium may stray into the eye through trocar even during vitrectomy. One of the possible causes was the risk of the noncontact wide-angle viewing system.