Today, the traditional File Server does not seem to be the only one and no longer the good enough way to manage documents for many organizations. Many have chosen SharePoint to improve their managing of documents and cover the File Server as much as possible. However, the use of SharePoint still seems to be lagging behind. To understand what influences the adoption of SharePoint Document Management System and be able to use this information can contribute to a better implementation and wider use of the system. User adoption of SharePoint Document Management System is studied in this thesis. The research is done through a case study. The data was gathered with qualitative interviews and observations. 16 interviews were conducted and these interviews with users were transcribed and analyzed. Results indicate that not all users are keen to use SharePoint because of lack of encouragement, information, skills and training. An adoption plan using Rogers Innovation Decision Process and based on the theory and findings, was suggested with the purpose of moving users to SharePoint from File Server. In order for an organization to successfully implement SharePoint Document Management System, understanding of potential adopters and the factors that influence their adoption decision is important. The findings indicate that perceived benefits and managerial training are main variables in processing adoption. The study can contribute to understand users behavior and has practical implications for organizations concerned with adoption of a new technology.