Many educators view school climate and student achievement as separate considerations. For some, the idea of promoting a high quality climate can seem like a luxury in the face of the current high stakes assessment climate in which student achievement gains are the paramount consideration. However, the results of this study suggest that climate and student achievement are related. In fact, the quality of the climate appears to be the single most predictive factor in any school's capacity to promote student achievement. The purpose of this study was to explore the relationship between student academic achievement and various elements within the domain of school climate, and to examine the nature and potential causality of that relationship. The paper also seeks to derive implications for practice including a possible fundamental conceptual framework for climate quality and function and an operational roadmap for moving from a less functional to more functional climate. The study examined school climate and achievement at 30 urban public schools. The sample of schools was drawn from a large geographical area and reflected schools from diverse ethnic and socio-economic communities. Each school assessment team administered the Alliance for the Study of School Climate (ASSC) School Climate Assessment Instrument (SCAI). The team at each school incorporated a standard protocol and surveyed a minimum number of participants (N = 30+ students, 10+ teachers as well as 10+ staff and parents, with most sample sizes being larger). Focus group data were also collected. California State Academic Performance Index (API) and Similar School Rating (SIM) scores (published by the state), were used to measure student achievement at each school. The results of the study confirmed a strong relationship between the quality of school climate and academic achievement levels. While the direction of the causality between the two variables is not entirely indicated by the data, the substantial relationship between climate and SIM rating suggest that a conclusion can be drawn that, to a good degree, better climates led to achievement, and were not simply a byproduct.