Data published on the official website of the NYC DOE indicated that slightly less than half (42%) of NYC students in grades three through eight are not proficient in ELA, and one quarter of them (25%) are not proficient in Math. School reform based on Hirsch's Cultural Literacy provided an additional dimension to exploring school reform and meeting educational and academic goals for the NYC's school children. The purpose of this study was to examine the impact of Core Knowledge curriculum on student reading achievement by studying the performance of a selected cohort of fourth grade students during the NYS ELA during 2008 and 2009. Quantitative research incorporating an ex-post facto, quasi-experimental, repeated measures model was implemented as a design for this study. Data analysis was performed using SPSS and G* Power software. Data analysis concentrated on the statistical findings of individual student performance during the standardized assessments obtained from the NYS ELA Exams of 2008 and 2009. The setting for this study was voluntary participation of NYC Public Schools grades K-5 identified as Control School (CS), and NYC Public Schools PK-4 identified as Experimental School (ES) that belonged to the Knowledge Network L.S.O. Both schools were located in Brooklyn, belonged to District 19, and received Title I funding. Statistical findings supported the idea that Core Knowledge curriculum increases reading achievement. The ES demonstrated higher mean scores during the NYS ELA 2009 assessment in comparison to the CS (M = 661.44 vs. M = 659.13, p < 0.05). This difference suggests that Core Knowledge curriculum may have an impact on fourth grade reading achievement. The study provided evidence on the effectiveness of the implementation of a knowledge-based curriculum on reading proficiency. Future research on Core Knowledge curriculum from Kindergarten to sixth grade may determine whether this is an effective alternative to state or district curriculum for improving literacy and closing the achievement gap between advantaged and disadvantaged students.