The purpose of this paper is to present results of introducing an agile process based on extreme programming, XP, in an evolutionary and maintenance software development environment. The agile process was introduced to a large software development organization. The process was applied by a team during eight months. The conclusions indicate that it in this case is more difficult to introduce XP, in its original appearance, to the case environment than to less complex environments. The complexity of the organization made it necessary to redesign many of the practices in order for them to fit the needs of the software development team.