Objective: To present the 1-year ocular outcome data from 2759 preterm infants. Design: Data from all untreated eyes were tabulated. Retinopathy of prematurity (ROP) was listed by the lowest (most posterior) zone and highest (most severe) stage reached during the acute phase of ROP, based on examinations conducted at least biweekly. Setting: Examinations were performed at 23 regional study centers. Patients: The natural history cohort of the Multicenter Trial of Cryotherapy for ROP. Main Outcome Measures: Ocular structure and visual performance. Results: The worst posterior fundus outcome rates were in eyes with zone I, stage 3 disease (59.3% unfavorable outcome) and zone II, stage 3+ ROP involving nine to 12 sectors of 30° (43.9% unfavorable outcome). Eyes with zone II ROP without plus disease or with zone III ROP are at very low risk (!1%) of unfavorable outcome. Conclusion: The more posterior the zone of ROP and the greater the extent of stage 3+ disease, the greater the unfavorable outcome rate. © 1994, American Medical Association. All rights reserved.