Background/Context: Although prior research shows that the nature and extent of private tutoring practices vary significantly from country to country, differences between Eastern and Western countries in terms of their cultural and institutional aspects of private tutoring choice have not been closely examined. We need to bridge the gap by studying the phenomenon of private tutoring more broadly as both an individual and a collective choice, and by accounting for its variations within and between countries. Objective: The objective of this study is to describe variations in the prevalence and causes of private tutoring around the world and to understand the differences between Korea and the United States in terms of their unique needs for private tutoring and policy responses. It helps better understand the phenomenon of private tutoring more broadly as both an individual and a collective choice by accounting for its variations within and between countries. Research Design: This study draws on secondary analysis of the 1995 Third International Math and Science Study (TIMSS) eighth-grade student and teacher survey databases that provide information on participation in after-school math private tutoring from 41 countries, including Korea and the United States. In addition, data from United Nations Educational, Scientific and Cultural Organization (UNESCO) yearbook are analyzed for information on the status of public education. Independent samples t tests, correlations, multiple regression methods, and logistic regression methods are used to examine the relationships between private tutoring and related factors. Findings: Although after-school private mathematics tutoring is prevalent among eighth-grade students across the TIMSS nations, there are significant between-country and within-country variations in tutoring needs and participation rates. After-school private mathematics tutoring is observed more in countries with relatively poor schooling conditions and lower academic achievement. However, a critical difference between Korea and the United States is noted: Tutoring in Korea serves primarily enrichment needs for higher achieving college-bound students, whereas tutoring in the United States is primarily for meeting remediation needs of lower achieving students. Further, the two countries diverge in their policy responses to tutoring needs: Private tutoring in Korea is seen as a threat to public education and has been regulated by the government, whereas private tutoring in the United States is seen as bolstering public education and receives support from the government. Conclusions: Private tutoring may function as a double-edged sword. On one hand, private tutoring stems from collective needs for providing supplementary education as compensation for limited schooling opportunities and from individual needs for academic remediation. On the other hand, private tutoring often serves high-achieving students for enrichment or college preparation, which may erode the idea of equal educational opportunities as envisioned by public schooling. The policy challenge is capitalizing on private tutoring as bolstering academic excellence and equity in public education, while counteracting its potential threats to public schools.