OBJECTIVES:The goals were to determine optimal screening criteria for retinopathy of prematurity (ROP) in 7 neonatal units in Rio de Ja-neiro, Brazil, and to explore the workload implications of applying dif-ferent criteria. METHODS:Infants with birth weights of 2000 g or gestational age of 37 weeks were examined by 3 ophthalmologists in 7 of the largest units inRio de Janeiro, during a 34-month period. ROPwas classified by using the international classification, and laser treatment was given to infants developing type 1 ROP. RESULTS:A total of 3437 (87%) of 3953 eligible infants were examined, of whom 124 (3.6% [range: 2.1%–7.8%]) were treated. Eleven infants were treated for aggressive posterior ROP. Appropriate screening cri-teria for the 2 NICUs with high survival rates (ie, 80% among infants with birth weights of 1500 g) would be 1500 g or 32 weeks. For NICUswith lowsurvival rates (ie, 80%), appropriate criteriawould be 1500 g or 35 weeks. UK, US, and previous Brazilian criteria would all miss infants needing treatment. CONCLUSIONS:ROP programs in Brazil should use the wider crite-ria of 1500 g or 35 weeks until further evidence-based criteria become available, although this would mean a slight increase in workload across the city, compared with use of the narrower cri-teria in the better units. Whether survival rates can be used as a proxy to indicate screening criteria requires further investigation.