This masters thesis aims to advance information and communication technology (ICT) adoption research and practice by examining ICT adoption and diffusion in large-scale enterprises from a sociomaterial perspective. Within a qualitative study, semi-structured interviews and observations were made in a large-scale enterprise with a focus on the emerging ICT tools Microsoft OneNote and SharePoint. The data was analyzed and interpreted with the Gioia methodology to understand the process and the involved actors. The findings reveal the importance of network effects and that ICT is not stable but continuously changes when it is being used. Resistance even occurs with small, very trivial and sometimes even self-initiated changes and was identified not only as a prevention but also as an activator of ICT adoption and diffusion. Concerning internal networks and individuals who are actively searching efforts for new ICTs, organizations need to focus on early adopters and support them in their promotion of widespread ICT. Moreover, organizations need to be aware of the danger of the unexpected growth of ICT solutions and initiate ways of prevention. This study advances ICT adoption research by developing a framework consisting of influential ICT adoption and diffusion determinants to explain how actors initiate and adopt new ICT autonomously.