Children diagnosed with retinoblastoma in the first year of life present with differences in laterality, stage, signs, symptoms, and respond differently to treatments when compared to older children. Of those children diagnosed in the first year of life (between 1958 and 1983 inclusive), 280 were bilateral and 121 were unilateral, the most common stage of diagnosis (for unilateral and bilateral) was Group V, and children were affected equally by sex. Children examined in the first three months of life were more often seen because of a positive family history of retinoblastoma, rather than leukocoria. Children who were treated in the first year of life frequently develop second nonocular tumors because they harbor the germinal mutation and receive radiation.