The aim of this Bachelor's thesis is to examine library directors' views on weeding in Swedish public libraries. The research questions posed are: What formal goals and criteria govern the weeding process?; How are these goals and criteria accounted for?; How do the library directors view the weeding in relation to the roles of the collections? The theoretical framework consists of a division of weeding criteria inspired by Stanley J. Slote, and a slight adaptation of Michael K. Buckland's roles of collections. The empirical material was gathered through semistructured interviews with library directors and analyzed using the above theories as structural tools. The results show that written guidelines and criteria are deemed unnecessary and awkward and are consequently not used. The weeding process described mainly uses circulation-based lists to identify weeding candidates, which are then judged on an individual basis using a mixture of subjective and objective criteria. The primary motives for weeding are that the material should be up-to-date and inviting to the users. Weeding is regarded as important for the distributing role of the collections. Unused material is viewed as problematic as it prevents browsing users from finding material that interest them. Weeding decisions invoking the archival and bibliographical roles of the collections are seen as hard to justify when conflicting with the distributing role. A discrepancy between an objective and a subjective stance towards the weeding process is prominent in much of the library directors' reasoning.