Instant messaging has been widely utilised by a variety of types of organisations to improve the efficiency and effectiveness of internal communication and knowledge management (KM). To date, though, the continuance use of enterprise instant messaging (EIM) and its impact on KM outcomes have not been well understood in both academia and practice. This paper uses the decomposed theory of planned behaviour to explore factors that influence continual usage of EIM applications within organisations, as well as the impact of the continuance use decisions on knowledge creation, transfer, and retention within organisations. Our results are useful in developing guidelines and strategies to increase the likelihood of the continuance use of EIM and to improve the potential outcome of its use within organisations.