Purpose: The ongoing challenge to sustain school learning and improvement requires schools to explore new ways, and at the same time exploit previous experience. The purpose of this paper is to attempt to expand the knowledge of mechanisms that can facilitate school learning processes by proposing boundary activities and learning mechanisms in which principals can engage to promote learning processes. Design/methodology/approach: The authors refer to Bourdieu's theoretical approach that human actions occur within fields of interaction. The authors delineate principals' internal and external boundary activities as mechanisms for promoting school learning processes while acknowledging that principals are embedded within competing fields, encompassing demands from the economic, political, and even global fields. The authors discuss how the principal boundary activities can not only facilitate the exploitation of knowledge embedded in the school system, but also the exploration of external knowledge across multiple fields of interaction. The authors then present the principal learning mechanisms as complementary activities to school learning improvement. Findings: Promoting school learning processes may require constant management of the school learning boundary so that the school neither becomes isolated from its environment nor loses its capacity for knowledge integration and exploitation. The boundary activities, combined with learning mechanisms, can enable the principal to balance these competing demands. Originality/value: The organizational learning processes of exploration and exploitation have been under-investigated in the educational context, as to the role of the principal in balancing the tension between these processes. This study conceptualizes boundary activities and learning mechanisms, suggesting a framework through which principals can engage to promote school learning.