This thesis is based on the assumption that the society in which we live is changing and that we are entering into the information society. This change will affect the public libraries in various ways and the libraries will have to be prepared to make adequate changes in their organizations. Based on the theories of Eric Rhenman and Richard Normann, dealing with how organizations act when changes in their environment occur, we have interviewed 10 public library leaders to find out how hteir respective libraries have acted in this situation. The results show that libraries have made some changes in their organizations to meet the environmental changes. Although not changing their old mission, all libraries have computerized and have had to raise the librarians educational level. However, only small changes have beenmade in their work towards the environment. Changes of this kind may become necessary in the future.