There is growing support for the role of genetic factors in the development of retinopathy of prematurity (ROP), a serious visual morbidity resulting from preterm birth. We used both candidate gene and data-mining approaches to investigate the role of genetic polymorphisms in the development of ROP. Our study population consisted of 330 infants, less than 32 wk gestation, and their parents. We initially studied 24 single nucleotide polymorphisms (SNPs) in 11 candidate genes. Using a family-based analysis strategy, we found an association between SNPs in the EPAS1 gene and the development of ROP (p = 0.007). Logistic regression analysis showed three SNPs associated with development of ROP, two in the CFH gene (p = 0.01) and one in the EPAS1 gene (p = 0.001). Extending this analysis to include genotyping data from a larger genetic study of prematurity (455 SNPs in 153 genes), we found SNPs in five genes associated with the development of ROP: IHH (p = 0.003), AGTR1 (p = 0.005), TBX5 (p = 0.003), CETP (p = 0.004), and GP1BA (p = 0.005). Our data suggest that genetic risk factors contribute to the development of ROP.