In 1991, one year after the Namibian independence, the Ministry of Education and Culture was organised in six departments and six regional directorates. The regional directorates were established as early as in 1991. The establishment of the regional directorates was the first step towards decentralisation of education management, which took a form of de-concentration. During the late 1990s, the regional directorates were subdivided into thirteen regional education directorates to be in compliance with the central government policy of decentralising functions from the head offices of various ministries to the regional administrations in the thirteen regions. During 2000, the Namibian Ministry of Education introduced cluster-based school management as a decentralisation reform, granting authority and responsibility for managing school supervision and in-service training for school managers and teachers to clusters, to be implemented in all the thirteen education regions. Cluster–based school management reform has been adopted as a strategy for improving school supervision and teaching in Namibia. However, there is little empirical evidence on the effects of school clustering on the quality of teaching in Namibia. This study examined the implementation of cluster-based school management reform in the Namibian primary schools. The specific focus of the study was to assess: (1) the implementation of cluster-based school management reform in the Namibian primary schools; and (2) the relationship between cluster-based school management reform and improving teaching at classroom level. The data for this study were collected through: (1) survey research in thirty-seven primary schools in five regions: Caprivi; Erongo; Hardap; Karas and Kunene, and (2), case studies, based on interviews; focused group discussions; informal conversations; observations; and document analyses in the three primary school clusters in two of the five education regions. The study’s main findings are that the implementation of cluster-based school management reform has been constrained by resource scarcity and reluctance to share resources; potential threat to the authority of school inspectors and school principals; and incongruence between the ideologies existed prior to the introduction of the reform and the democratic ideology. The other main finding from this study is that there is insufficient evidence to show that the teaching methods of teachers who have received support from the school management reform are notably different from those who have not. This study demonstrates a number of obvious missing links between cluster-based school management and improving teaching, because the reform lacks: (1) clarity, guidelines and resources to support and monitor teaching in schools and at classroom level; (2) clarity on the roles and responsibilities of key implementers in improving teachers’ teaching practices; (3) capability to transform school traditions and culture into a culture which transforms teaching in schools; and (4) clarity on how teacher involvement can be utilised to improve teaching in schools. This study concludes that there is no evidence from this study that cluster-based school management reform relates to improving teaching.