Purpose: To study the characteristics of late-onset retinal detachments in patients with regressed retinopathy of prematurity (ROP) and the condition of their fellow eyes. Methods: We carried out a retrospective review of 29 patients (38 eyes) who had been treated at two institutions, one in the US and the other in Japan, between 1986 and 1997. The age at the time of treatment ranged from 6 to 51 years (mean = 23.1). Five of the 38 eyes with tractional detachment were treated with either open-sky vitrectomy, closed vitrectomy, or scleral buckling; 27 of the 38 eyes with rhegmatogenous retinal detachment underwent scleral buckling or closed vitrectomy or both. The remaining 6 of the 38 eyes had subclinical rhegmatogenous detachment and were treated with photocoagulation or cryopexy, or followed without treatment. The most characteristic retinal breaks were multiple holes with a prevalence of equator and posterior types. Results: Overall, anatomical reattachment was accomplished in 27/32 eyes (84%) that underwent surgery. Two thirds of the patients who underwent vitrectomy either initially or at a later time had poor postoperative visual acuity. More than half of the fellow eyes had retinal detachment and others had various characteristic fundus changes of regressed ROP. Conclusions: Long-term, probably life-long follow-up of high-risk patients is necessary so that diagnosis and treatment can be instituted at an early stage of retinal detachment.