The aim of this study was to investigate the extent to which principals of private schools in jerusalem apply the "knowledge management" concept at their schools. The study had utilized Nonaka, Toyama and Kono´s theory of knowledge production (Nonaka, Toyama & Kono, 2000). In this regard, several studies which are connected to knowledge management had been reviwed, these could basically be classified into three main categories: reasons and justifications for applying knowledge management in organizations, knowledge management procedures and strategies, and the role of the leader in the application of knowledge management. A quantiative- descriptive methodology had been employed in order to fulfil the goal of this study. As to statistical procedures, mean and standard deviations were calculated using the SPSS. In order for the study to achieve its goals, a questionnair was used, the quesntionnair´s validity and reliability had been varified and then distributed to the whole population of the study, the population consisted of all private schools principals, by a total of (173) both males and females in Jerusalem. The researcher only received (147) surveys back, therefore, so the response rate was (84.8%). Results revealed that all survey items scored high, which means that the private schools principlas in Jerusalem apply the knoweldge management concept to a large extent. Discussion of the results had been provided and the reseracher arrived at some recommendations in this specific area, one of which had been on the practical level: designing a training program or workshops for the private schools principals in order to clarify the basic concepts which are connected to knowledge management, providing courses in using computers to organize and save information, enhancing the internet connection in schools to facilitate the exchange of experiences, create a job title for a person who could be encharge of knowledge management, sharing, and organization to lift the load off the principals back, and finally to develop Palestinian school curriculams in areas of knowledge that would help students produce it. As for future research, the researcher in this study recommended the following: a study to investigate the degree to which the head of departments in Jerusalem apply the concept of knowledge management at and to compare the results with the current study. Additionally, a study in the aspects that the teachers develop at the schools when applying knowledge management at their schools and how this affects students´ achievement, and finally a study that would create a suitable strategy for the Palestinian reality in order to ensure effective application for knowledge management at the Palestinian private schools..