Much has been written about the education policies and practices that countries and schools are putting in place. At the other end of the spectrum, accountability systems and assessments such as the Program for International Student Assessment shed light on the results that are achieved. Much less is known, however, about how policies and practices are actually implemented at the frontline in the daily work of teachers and school principals. To find out, the Organisation for Economic Co-operation and Development conducted the Teaching and Learning International Survey in 2007-2008, which surveyed more than 70,000 lower secondary teachers and their school principals in 23 countries, representing a workforce of more than 2 million teachers. The aim was to provide comparative insights into the conditions of teaching and learning at their schools, the leadership in their schools, their preparation and professional development, and the feedback and appraisal that they do--or do not--receive. This article presents key findings from this survey. Naturally, reports from teachers provide only one perspective on what goes on in schools, and that perspective needs to be put in the context of other information sources. However, the perspective of teachers is crucially important because the best policies and practices will only yield results if they are effectively implemented, and the bottom line is that the quality of an education system cannot exceed the quality of its teachers and their work. (Contains 5 figures.)