The main purpose of this thesis is to investigate how books are weeded in some Swedish public libraries today. It tries to shed light on some of the problems and obstacles that may arise, and on the criteria used by staff for weeding. I also hope to build a model for weeding, based on the results of my investigation. The method I have chosen for my work is qualitative interviews. The results of my thesis indicate that weeding is not the top priority of the staff at the investigated libraries. Apart from one library, which had a very general local policy on weeding to aid the staff, none of the other libraries had a written policy. Time for weeding is claimed to be scarce. Different kinds of weeding aids are suggested, such as written weeding policies, handbooks on different literature genres, networks including experts etc. The model I propose suggests the use of written policies on collection development, the use of a more systematic approach to weeding, more discussion among the staff on weeding criteria and the use of weeding aids such as handbooks, computer systems etc.