Purpose: The purpose of this study is to explore the interaction between information communication technology (ICT) and the school's organizational structure, and propose an analytical model based both on Luhmann's system theory and empirical findings. Design/methodology/approach: The approach of building a theory from a case study research along with an instrumental multi-case study method were applied to analyzing nine Israeli schools that successfully implemented ICT-based pedagogical innovation. Findings: The findings suggest that ICT generates three kinds of differentiation within the school's structure: segmentation, stratification and functional differentiation. The type of differentiation correlates with the school's communication and set of contingencies which includes ICT usage types, leadership style, time and space arrangement, source of expertise, and the champions--those who bear the burden. All the differentiation types were found to increase internal complexity and enhance school adaptability, and in a recursive process, affect school communication and its sensitivity toward further ICT integration. Research limitations/ implications: The fact that the chosen schools demonstrated extreme cases of successful ICT integration might limit the generalizability of the findings, but nonetheless it offers a significant contribution to the development of a substantive ICT and school structure theory. Practical implications: Supporting ICT integration called for intervention at the school's top management level; supporting an initial ICT-based project enhances the school's control over the implementation process, and provides schools with additional resources. Originality/value: This study bears a substantive theory regarding ICT and school structure, and fosters new insights and propositions for further research. (Contains 3 tables.)