This article aims to identify threats perceived by Swedish public library directors as the most prominent. A web questionnaire was sent to public library directors in all of the Swedish municipalities. The data were analysed using qualitative content analysis. The findings reveal that the main threat was considered to be the tension between the current activities of the public library and the expectations of the public, or of local decision makers. One reason for the lack of correspondence between activities and expectations is that public library managers regard the expectations on the public library as unrealistic. Another reason is that lack of resources prevent public library staff from meeting many of these expectations. Public libraries are thus prevented by both ideological and practical barriers in fulfilling expectations.