The purpose of this study was to examine the effect of the Primrose® Balanced Learning® Curriculum on young children's science performances. The sample of this study included 158 children attending two private preschools. The study utilized a single group pre-post-test design. The children were tested before and immediately after the implementation of the Primrose® Balanced Learning® Curriculum to assess their science performances. Children's interest in learning science was assessed before the implementation of the curriculum. The results demonstrated that the observed change in children's science scores from pre to post assessment was substantial, corresponding to about a medium effect size. Although both sexes made progress in their science performance, the girls made greater gains. Boys and girls did not differ in their interest in learning science, but prekindergartners regardless of their sex were more likely to demonstrate higher interest in learning science than their younger peers. The preliminary findings of this curriculum development effort suggest that the systematic instructional framework based on a balanced learning view has potential to promote young children's learning of science.