Purpose - This study aims to investigate the effectiveness of information and communication technologies (ICT) tools to enable the sharing of tacit knowledge in organisations. Sharing knowledge is defined as the interactions between human actors whose raw material is knowledge (Helmstadter, 2003). This behavior is critical to the creation and application of organizational knowledge. In relation to the existing types of knowledge, we incorporated the most used classification in the literature, postulated by the philosopher Michael Polanyi (1958), who suggested that there are two types of knowledge: tacit and explicit. Based on this, a way of defining sharing knowledge is the process by which employees exchange tacit and explicit knowledge (Nonaka, 2007). Tools based on information and communication technologies (ICT) have been traditionally used to share explicit knowledge, while in the literature there is no clarity about the effectiveness of these tools to share tacit knowledge (Panahi, Watson and Partridge, 2013). Although, research on the subject is not exhaustive, there are reports of the ineffectiveness of ICT tools to share tacit knowledge (Abadi, Hussini, Sriraj, Thienthong and Finley, 2009), as well as reports of their effectiveness to share tacit knowledge (Razmerita, Kirchner and Nabeth, 2014). The debate about ICT tools as facilitators of tacit knowledge sharing suggests a current gap in the knowledge management literature (Panahi, Watson, and Partridge, 2016). In our study, we found that those ICT tools that facilitate dialogue, for example, audio conferences and text messages, are effective to share tacit knowledge and that ICT tools that do not facilitate knowledge dialogue, for example internet and emails, are not effective to share tacit knowledge. Design/methodology/approach - We adopted a quantitative approach. Data were collected using an instrument that measures types of knowledge and tools to share knowledge. Participants were 217 knowledge workers in New Zealand and researchers who attended a knowledge management conference in the United Kingdom. Originality/value - This study contributes to clarify if ICT tools are effective to share tacit knowledge. We found that some ICT tools are ineffective to share tacit knowledge. However, we also found that some tools based on ICT can facilitate knowledge sharing, specifically those that permit dialogue, for example audio-conferencing and text messaging. Practical implications - The outcomes of the application contribute to redesign strategies and activities of organisational communication and collaborative work, to make the exchange of tacit knowledge more productive in the processes of creation and application of knowledge.