This study examines the multidimensional and hierarchical structure of achievement goal orientation measured by the Inventory of School Motivation. The instrument consists of eight different scales with 43 survey items (ranging from three to seven items each). Each scale reflects one of eight specific dimensions: task, effort, competition, social power, affiliation, social concern, praise, and token. The study also examines the ability of these eight first-order factors to define four general second-order factors--mastery, performance, social factors, and extrinsic factors--as well as one third-order factor, general motivation. Participants came from seven different cultural groups in high schools in Australia (n = 4,787), Hong Kong (n = 697), the United States (n = 2,660), and Africa (n = 819). Nested confirmatory factor analyses support a multidimensional, hierarchical school motivation construct. The model was invariant across cultural groups. The findings provide a strong theoretical structure and tool for further school motivation research. Items, alpha, mean, and standard deviations for the Inventory of School Motivation (ISM) is appended. (Contains 6 tables and 2 figures.)