Psychological Services Ze far, IsraelThis study describes a community-wide experimental change program that was initiated by a school psychologist who served as a system facilitator and change agent. The program strived to improve social climate in the classroom, and was executed in the fourth-, fifth-, and sixth-grade classrooms of an entire school system in northern Israel. This paper describes the program's design and rationale as well as its activities. Thirtythree classrooms participated, all of which were assigned randomly into three treatments: two experimental programs working on topics in classroom life, one in small-group settings and the other in whole-class settings, and one control (no program). Classroom climate was measured twice (pre-and posttest) during the school year by answering a modified Hebrew version of the Walberg and Anderson questionnaire developed by Hertz-Lazarowitz and Sharan (1979). Results indicated that increase in positive social climate control occurred in the experimental small-group program in all grade levels. The whole-class treatment showed improvement in higher grades, whereas the no-program control classrooms showed a significant decrease in classroom climate during the year. Three main factors were explained as contributing to the impact of the program on positive social climate. From an organizational perspective, (a) the participation and collegial support of teachers within the school with (b) the active leadership of the school psychologist helped improve social climate. Lastly, (c) the children's responses revealed the importance of experiencing cognitively and affectively the content of the program. This program, with certain modifications, became a consistent part of the school curricula.