Tacit knowledge is a contemporary area of research that is being explored for its ability to aid in developing a firm’s knowledge capital. At the same time little work has yet been undertaken on the structure of companies and other factors such as human networks or usage of information technology that may impact on how likely tacit knowledge can be transferred from one individual or group of workers to the next. An empirical study in three IT firms of varying sizes, type and structure has been conducted. The methodology included tacit knowledge testing in individuals, Formal Concept Analysis to interpret tacit knowledge results and Social Network Analysis to map communication flows between staff. Initial research indicates there is likely to be a positive correlation with organizations whose structure and work design promote face-to-face contact and have employees sharing close physical proximity, being more successful at tacit knowledge sharing.