Companies have demonstrated growing concerns about the adoption of agile methods in their internal software development organization, aiming to get the benefits related to productivity increasing, software quality improvement, better delivery predictability, better relationship between IT and business areas, better delivery velocity, and a better way to handle requirements change. However, the same companies already have consolidated organizational structures and processes, which get into conflict with values and practices established by the agile methods and Scrum specificaly, hindering its adoption. This study presents the major dificulties in Scrum adoption in organizations that make use of non-projectized structures and plan-driven processes. To identify those dificulties, interviewes were conducted and questionnaires were applied in three brazilian companies that make use of IT to support their business, with similar structure and process. After the result analysis, the major points of dificulty in Scrum adoption were identified and then consolidated in a way that allow companies to identify adjustment points in its processes to improve the adoption of Scrum.