Knowledge Management Systems (KMS) have been employed by organizations to facilitate knowledge sharing. However, previous studies have found that the implementation of KMS is often unsuccessful due to the reluctance of employees to use these systems to share knowledge. This study is intended to examine the factors potentially influencing knowledge sharing which may also affect the success of knowledge management systems (KMS), and to explore the relationships between these factors. The focus of this study is the success of KMS in healthcare, since there is little research in this area. The research model is proposed as an improvement to the existing KMS Success Model by considering some external factors that may influence knowledge sharing. A better understanding of the factors that motivate knowledge sharing would encourage more use of KMS and would provide better development of KMS in healthcare. Further empirical research will be conducted to test and validate the model.