The work presented here deals with troubling issues about schools. The starting point is research on Australian schools, particularly a recent study on disadvantaged schools, but the discussion is equally addressed to readers in other countries. There are three key reasons why social justice matters to everyone connected to the school system, and these are (1) the education system is a major public asset; (2) the education system is likely to become even more important in the future; and (3) teaching and learning, as social practices, always involve moral values and issues of justice. An education that privileges one child over another gives the privileged child a corrupted education, even as it affords a social or economic advantage. Part 1 discusses the principles involved in the provision of social justice, poverty and compensatory education, and knowledge and society as they relate to curricular justice. Part 2 focuses on practical aspects of social justice in the schools, with discussions of teaching, assessment, the Disadvantaged Schools Program of compensatory education in Australia, and research needs. An appendix gives examples of practice in disadvantaged schools. Three figures illustrate the discussion. (SLD)