The purpose of this study was to explore the practices and processes executed by middle managers as practitioners during the implementation of strategy. In order to do that, this study investigated the problem of strategy implementation, analysed existing literature, identified the gaps, and explored the roles of middle managers in terms of strategy practices and processes, specifically in the South African Defence Evaluation and Research Institutes (DERI) context. Resources, time and effort are applied to formulating strategy but less of these to the execution of the strategy which includes the emotions, motivations and actions that are intangible during the implementation of strategy. The study therefore attempts to answer the following research question: What practices and processes are employed in strategy implementation in DERIs in South Africa? The literature study was undertaken with the objective of mapping the research problem and to highlight, through critical discussion, the latest work done on the subject of this study. The gap in relation to research work was identified and the contribution is clear that not much work has been done in this environment. Research is a systematic process where information on a specific topic is gathered in order to increase understanding of that phenomenon. A qualitative study was performed and data was obtained from several institutes through interviews, documents and questionnaires in order to build a rich database that could be analysed for the required output. Engagement with the first level of management as well as the next level management teams ensured that a representative population group was used during this study. The data was organised, categorised, interpreted, identified, synthesised and generalised. The quotations identified from the text were coded through inductive coding and grouped into categories until a logical theme, category and concept was formed. The objective of this research was to investigate, identify and understand what the strategy practices and processes are that make highly technical and scientific institutes execute strategies successfully. The study provided insight into and clarity on the complexity of the strategy implementation process as executed by middle managers, particularly in the South African context. The link was explored between formulation and implementation as applied by middle managers as practitioners and the practices and processes in use were identified. It was demonstrated that the outcome of this research is applicable to the research problem and also provides an understanding of the phenomenon, namely strategy practices and processes in use at the Defence Evaluation and Research Institutes. It can therefore be concluded that the research objective was achieved. / Business Management / D.B.L.