This study conducts a meta-analysis using hierarchical linear modeling (HLM) to address the questions of the extent of gender differences in reading, whether or not these differences apply similarly across English and non-English speaking countries and decrease with age. Female secondary students performed 0.19 standard deviation units above their male peers, regardless of age, language of instruction, and whether effect sizes were based on mean differences or correlation coefficients. However, differences emerged between assessment programs, with recent Australian Studies, the National Assessment of Educational Progress Studies (NAEP) and the Programme for International Student Assessment (PISA) reporting greater gender differences.