Although many factors combine to make a successful school, most people agree that quality teachers and school principals are among the most important requirements for success, especially when success is defined by the ability of the school to raise the achievement of its students. The central question for this study is how the quality of the teachers and principals in high poverty schools in North Carolina compares to that in the schools serving more advantaged students. A related question is why these differences emerge. The consistency of the patterns across many measures of qualifications for both teachers and principals leaves no doubt that students in the high poverty schools are served by school personnel with lower qualifications than those in the lower poverty schools. Moreover, in many cases the differences are large. Additional evidence documents that the differences largely reflect predictable outcomes of the labor market for teachers and principals. Hence, active policy interventions are needed to counter these forces if the ultimate goal is to provide equal educational opportunity. (Contains 11 tables and 4 figures.)