This study investigated the mediating role of purposeful organizational forgetting in the relationship between distributed leadership and organizational development of elementary school teachers. In today's world, distributed leadership is recognized as a new approach in educational management that allows teachers to actively participate in the decision-making and school management process. On the other hand, purposeful organizational forgetting is recognized as an essential process in organizations that helps them get rid of unnecessary and ineffective information and focus on useful knowledge and experiences. This study seeks to investigate whether purposeful organizational forgetting can act as a mediator in the relationship between distributed leadership and organizational development. The statistical sample size of this study includes 153 elementary school teachers in different schools who were selected through random sampling. Data were collected using standard questionnaires and analyzed using statistical software such as SPSS and AMOS. The results showed that distributed leadership has a positive and significant effect on teachers' organizational development, and purposeful organizational forgetting, as a mediating variable, strengthens this relationship. These findings can help educational administrators and policymakers to better understand the role of organizational forgetting and design more effective strategies to improve leadership and organizational development in elementary schools. Also, this research can be used as a theoretical basis for future research in the field of educational leadership and knowledge management in educational organizations. Finally, it is suggested that training programs and workshops for teachers in the field of distributed leadership and organizational forgetting management be designed and implemented to help improve their performance and professional development.