The goal of this research is to provide an assessment of current status of socioeconomic differences in learning outcomes across school subjects. Learning outcome refers to academic achievement or academic competence tested through standardized paper-and-pencil instruments. To update the research literature on socioeconomic effects from a global perspective, this research seeks the most recent data available from international student assessments to identify challenges in reducing socioeconomic differences in learning outcomes. International student assessment is a procedure designed to obtain information about cognitive and affective outcomes of school-aged learners from different participating countries. International student assessments have long been considered a valid method for cross-national comparative research. Information gathered from international student assessments is often used for a variety of evaluative purposes, one of which is to examine the equality issues in learning outcomes. All existing international student assessments contain measures on family socioeconomic background and student learning outcomes, making it appropriate to use international student assessments for a global evaluation of socioeconomic differences in learning outcomes. International student assessments draw nationally representative samples, providing an ideal avenue to examine socioeconomic differences in learning outcomes at the national level and allowing international comparisons of socioeconomic differences in learning outcomes within and possibly across particular assessments. This research aims to analyze recent data from existing international student assessments to address the issue of the relationship between family socioeconomic background and student learning outcomes in multiple school subjects. International student assessments examined in this research include (a) Programme for International Student Assessment (PISA), (b) Third International Mathematics and Science Study (TIMSS), and (c) Civic Education Study (CivEd).