Across the educational systems of the world, few issues have received more attention in recent years than the problem of ensuring that elementary- and secondary-school classrooms are all staffed with adequately qualified teachers (Mullis et al., 2000; OECD, 1994, 2005; Wang et al., 2003). Even in nations where students routinely score high on international exams, the issue of teacher quality is the subject of much concern. This is not surprising. Elementary and secondary schooling is mandatory in almost all nations and children are legally placed in the care of teachers for a significant portion of their lives. It is widely believed that the quality of teachers and teaching are among the most important factors shaping the learning and growth of students. Moreover, this impact goes beyond student academic achievement. Across the world, observers routinely tie the performance of teachers to numerous, larger societal goals and problems--economic competitiveness and productivity, juvenile delinquency, moral and civic culture, and so on. In addition, the largest single component of the cost of education in any country typically is teacher compensation. Along with a general consensus among many nations that the quality of teachers and teaching is a vital resource, there is accordingly much concern surrounding how equitably this resource is distributed within educational systems. Indeed, some nations suffer from an apparent paradox--that despite an overall overproduction and oversupply of new teachers, there nevertheless appear to be substantial numbers of students without access to qualified teachers. This brief summarizes the results from a collaborative, comparative study of the qualifications of elementary and secondary teachers undertaken by a group of scholars, policy makers and senior education officials from six nations and one region: United States, Korea, China, Hong Kong, Singapore, Thailand, and Japan. The findings are the subject of a new report, A Comparative Study of Teacher Preparation and Qualifications in Six Nations (Ingersoll et al., 2007).