While projects in the Information Technology (IT) domain have been studied extensively, not much is known about the practices of knowledge work that is needed for IT projects to be brought together and enacted as temporary organisational structures. Building on the knowledge-as-practice perspective, we set out to explore collaborative work, which occurs through dialogic practices across knowledge domains in IT projects. Drawing upon multiple case study research in the IT industry, we run a qualitative analysis based on semi-structured interviews with the management level staff of six IT organisations. Based on the insights on IT projects in the six case organisations that varied in size and the degree of knowledge structure we develop a practice-based understanding of the collaborative practices of knowledge work. We identify three main practices of knowl-edge work in IT projects: a) expressing differences, b) co-creation, and c) mutual alignment, directing domain expert knowledge work at the collective level and towards shared project objectives. The practices emerged in the form of collaboration and as a function of cross-domain multi-disciplinary teams' alignment in IT projects. We offer novel insights into the essential role of the dialogue in collaborative knowledge work practices in IT projects, and their respective parent organisations.