This article presents the findings of research into quality management in Dutch elementary schools using theories of school accountability and school improvement as fundamentals. The study is based on data gathered from almost 1000 school leaders. It attempts to determine whether different types of quality management exist in primary schools. Schools are classified into four types of quality management. The results show that one cluster of schools developed an advanced type of quality management. When compared with the other clusters, schools of this type are unique in many ways. First of all, from the perspectives of school accountability and improvement these schools are the most active in terms of determining and improving their quality. Furthermore, this type of quality management produces a higher quality of teaching-learning than the other three types of quality management. Apart from this, it is interesting that the results of the study show that there are only slight discrepancies between quality assessments by the schools themselves (internal) and the judgements of the Inspectorate of Education (external). Furthermore, all four types of school support the quality indicators that the Inspectorate uses to asses the schools' quality management. However, interestingly, the more advanced type of quality management supports these indicators significantly more strongly than the other types. (Contains 1 figure and 7 tables.)