Purpose: The purpose of this study was to use meta-analysis to examine recent domestic articles related to attention deficit hyperactivity disorder (ADHD) in school-age children. Methods: After reviewing 213 articles published between 1990 and 2009 from and cited in RISS, KISS, and DBpia, the researchers identified 24 studies with 440 research variables that had appropriate data for methodological study. SPSS 17.0 program was used. The outcome variables were divided into five types: Inattention, hyperactive impulsive, intrinsic, extrinsic, and academic ability variables. Results: Effects size of overall core symptoms was 0.47 which is moderate level in terms of Cohen criteria and effects size of overall negative variables related ADHD was 0.27 which is small level. The most dominant variable related to ADHD was obtained from hyperactive-impulsive (0.70). Also academic ability (0.45), inattention (0.37), and intrinsic variables (0.29) had a small effect whereas extrinsic variables (0.13) had little effect on descriptive ADHD study. Conclusion: The results reveal that ADHD core symptoms have moderate effect size and peripheral negative variables related ADHD have small effect size. To improve the reliability of the meta-analysis results by minimizing publication bias, more intervention studies using appropriate study designs should be done.