Abstract
Everyone’s interest has been focused in recent years in the field of education, on the school climate and the educational administration, as they both constitute two catalytic factors of school effectiveness, directly related to other inner characteristics that form the unique identity of each school unit. The role of the school principal in the modern school concept is essential in the formation of the proper school climate as he can not only influence the professional satisfaction that the teaching staff enjoys but he can also aim at improving their effectiveness. The present study focuses on showing the importance of creating a positive climate in a school unit and the essential role of the principal- leader in the formation of such climate via the exhaustive and thorough research, analysis and synthesis of resources both from the Greek and foreign bibliography.