This chapter contrasts the notions of organizational culture and climate, and then uses the metaphor of health to conceptualize and measure the climate of secondary schools. First, the development of an organizational health instrument is detailed and profiles of healthy and unhealthy schools are described. Next, directions for administrating and scoring the health instrument are provided, and a hands-on example and interpretation of an actual school profile are presented. Finally, the chapter concludes with a brief review of research, implications, and cautions. In sum, a useful, reliable, and valid measure of school health is ready for teachers and administrators committed to improving the climate of their schools and for researchers interested in studying and changing schools.