Abstract-The key to understanding the development of competitive advantage is understanding knowledge and how it is managed and shared. Organisations not only need to understand comprehensively the concept of knowledge in order to manage it effectively, but also to create and maintain competitive advantages, especially as the business environment has become increasingly competitive. The aim of this study is to understand how the knowledge management concept can be harnessed as a vital factor in the enhancement of productivity, performance and the competitiveness of organisations. In this paper, we have used grounded theory strategy, which provides in-depth information relevant to KM implementation. Data were collected from face-to-face semi-structured interviews with 24 top managers from 19 different top-ranking companies operating in Saudi Arabia. It found that the most important factor influencing the success of KM implementation is the employees' willingness to participate in KM activities and share their knowledge. A theoretical model based on the findings of this study was developed and the theoretical and practical contribution to this model is discussed, as well as the findings.Index Terms-Critical successful factors (CSFs), employees' willingness, knowledge management (KM), organisational performance (OP).