In countries with a governance structure in which responsibility for the quality of education is shared between government and school boards, the past decades school self-evaluation has been stimulated as a way to encourage continuous quality improvement. However, working on the goals of quality assurance and school improvement at the same time is a challenge in general. To make a valuable contribution to both goals, the self-evaluation effort has to be of sufficient quality itself. In this article, we present a research-based framework for school self-evaluation (SSE) composed of both content and process factors that allows to evaluate the quality of self-evaluation in schools. We then used this model to evaluate the experiences in a comprehensive self-evaluation project that has been designed and used to help Dutch secondary schools promote the quality of student care. Our sample encompassed 79 Dutch secondary schools involved in this project. The findings show that the quality of SSE depends on the quality of the instruments (content) and process factors. However, to make a valuable contribution to school improvement and thereby the quality of education in The Netherlands more attention is needed for a balance between internal and external supervision and the role of school managers in the process of SSE. For future research more insight is needed in the challenges of meeting the content and process conditions of school self-evaluations, the governance and supervision issue at the level of schoolboards, the competence of change management in schools and the effects of SSE on the quality of education.