<p style="text-align: justify;">School quality has become a guiding concept that increasingly shapes educational planning and school development. For many decades, it has been a topic of significant interest, resulting in a wide-ranging and diverse research field. However, it is far from clear how school quality should be defined, what it should encompass, and how it influences student performance. The goal of this scoping review is to examine the existing evidence of the relationship between characteristics of school quality and student cognitive output/ student performance in secondary school. More precisely, it aims to (a) identify, (b) categorize, and (c) examine and evaluate the effects of characteristics of school quality affecting student performance and teaching characteristics in secondary school. In order to achieve these aims, we selected, clustered, and analyses 37 articles. The process was conducted by the research group through regular meetings, discussions, and consensus decisions. Our findings contribute to the comprehensive body of literature by identifying the following dimensions: <em>aims and strategies for quality development, leadership and management, professionalism, school culture</em>, and <em>resources</em>. Furthermore, the review revealed that although the field of school quality has been extensively researched, it lacks consistency, with many different operationalisations and definitions, making comparisons and syntheses challenging or even impossible. We believe that clear operationalisations and definitions are crucial to achieving comparability. Additionally, to achieve a standardized understanding of school quality and establish the categories internationally, uniform, theoretically sound, and content-related definitions of each category are necessary.</p>