This paper focuses on the current debate about educational quality in Kindergartens that has been taking place in Germany mainly since the 1990s. Set against a background of different theoretical conceptions of educational quality in Kindergartens, this paper introduces a common theoretical framework of educational quality (structure-process model) that differentiates between four major components: structural characteristics, educational beliefs, educational processes, and networking with families. Relevant national and international studies about educational quality in Kindergartens refer to this theoretical framework. In addition, the authors present standardized instruments that are also based on the structure-process model of quality. Furthermore, by drawing on the structure-process model of quality in Kindergartens, they report on national and international findings regarding the level of quality, prediction of quality, and effects of quality on child development. Finally, an outlook is given with reference to procedures for the development and improvement of educational quality in Germany.