The aim of this research is to study the relationship between Trust, Collaborative Culture, and Tacit Knowledge Sharing in Project Management as a source of Team Creativity in the context of delivering value through knowledge. There are numerous scientific papers indirectly pointing to the relationship between these constructs, however there isn't a work which would present the above relationship directly in one model which would also include Tacit Knowledge. Learning about the structure of this relationship is crucial today because of a growing awareness of the great significance of Tacit Knowledge Sharing in a present day economy. Tacit Knowledge in contrast to explicit knowledge is absolutely novel, which makes it truly advantageous. Tacit knowledge is specific: it is produced and stored in people's minds, thus creative culture and trust are significant for the act of tacit knowledge sharing which is a dynamic social process characterised by profound human interactions. Sharing informal knowledge is an informal voluntary act of the knowledge owner. It is impossible to formalise the act of commitment, for you cannot express your commitment in a not-commitment way. Bearing this fact in mind, the authors studied the relationship between Tacit Knowledge Sharing, Trust and Collaborative Culture as a source of Creativity. For this purpose, they conducted a study of 514 Polish professionals with different functions and experience in managing projects in construction industry. The data collected during the study has been analysed with the equal structural modelling method. The results indicate that a total effect of Trust on Tacit Knowledge Sharing is strongly mediated by Collaborative Culture. That interrelation suggests that team building is substantial even in such temporary organisations as project teams. Tacit Knowledge Sharing is closely related to Creativity which is a crucial part of innovation processes. This, on the other hand, is an indispensable condition for development. That points out to a new context of Tacit Knowledge Sharing as a key factor for value co-creation in project teams as a source of Creativity. What is more, in light of the presented research the essence of a Tacit Knowledge Sharing management process can be brought down to human resource management. Thus, it is the soft skills that seem to constitute key management skills. Practical implications resulting from the research suggest that hard substantive competences connected with, in this case, construction industry, are necessary, however not sufficient for creating an efficient temporary project team which is able to solve problems in a dynamic and creative way, and this ability often determines the project's success or failure. Delivering value through knowledge in project teams is making sure that knowledge which is necessary for effective action to take place is delivered. Delivering value through knowledge does not only require an efficient Transactive Memory System but most of all a diligent approach to human resource management, with special emphasis on the culture of collaboration, in order to ensure Tacit Knowledge Sharing, whose key element is the trust between team members.