The Teacher Education and Development Study in Mathematics, sponsored by the International Association for the Evaluation of Educational Achievement, is the first data-based study about mathematics teacher education with large-scale samples; this article is based on its data but develops a stand-alone conceptual framework to investigate the quality of teacher education among various countries. The framework includes five indicators: future teacher achievement, instructor effectiveness, coherence between universities and schools, courses/content arrangement, and overall effectiveness of teacher education programs. One of the findings provides indications that it is necessary to combine theoretical knowledge with practical teaching into teacher education; another finding is that for all countries involved, future teachers are less approving of the courses/content arrangement of teacher education programs than are program educators, thus perhaps lowering educators' motivation to improve the arrangement. The data also indicate that there is a high degree of synchronization and organization in teacher education programs in the United States; however, these programs still require further development and promotion of their future teachers' knowledge achievements. (Contains 9 notes, 6 tables and 3 figures.)