This paper aims at developing a measure for educational inequality for a large number of countries over time, using the concept of education Gini index based on school attainment data of the concerned population (or labor force). Education Gini could be used as one of the indicators of welfare, complementing average educational attainment, health and nutrition, income per capita, and other indicators of welfare. The paper presents 2 methods (direct and indirect) for calculating an education Gini index and generates a quinquennial data set on education Gini indexes for the over-15 population in 85 countries (1960-90). Preliminary empirical analysis suggests that: inequality in education in most of the countries declined over the three decades, with a few exceptions; inequality in education as measured by the education Gini index is negatively associated with average years of schooling, implying that countries with higher educational attainment are more likely to achieve equality in education than those with lower attainments; a clear pattern of an education Kuznets curve lists if the standard deviation of education is used; gender gaps are clearly related to education inequality, and over time, the association between gender gaps and inequality becomes stronger; and increases in per capita GDP (adjusted for purchasing power parity) seem to be negatively associated with education inequality and positively related to the labor force's average years of schooling, after controlling for initial income levels. Includes 11 notes, 12 figures, and 7 tables. (Contains 84 references.) (BT)