This paper presents a secondary analysis of the National Assessment of Educational Progress (NAEP) dataset. The study explores differences in the NAEP fourth, eighth, and twelfth grade reading scores by students' gender across the years 1992, 1994, 1998, 2000, 2002, and 2003. The study used the NAEP National Public School data. The statistically significant (p. less than 0.01 with effect size measured by Cohen's d) differences in reading scores by gender were consistent across grade level and years with females scoring higher than males. A discussion of the calculation and reporting of effect size with NAEP data is included as well as implications for the No Child Left Behind goals of "closing the gap." This paper presents the argument that the "child left behind" in reading is very likely to be male--from elementary school through university. (Contains 3 tables.)