Despite concerns about negative consequences for clients and permanent staff, temporary agency workers (TAWs) are frequently employed to manage staff shortages in personal social services (PSS) in Sweden and elsewhere. Drawing on qualitative interviews with thirty-four TAWs, managers and permanent social workers, this article aims to enhance our understanding of how TAWs are utilised in the PSS and the impact this has on (i) the preconditions for TAWs and (ii) the work environment for permanent employees. The findings suggest that TAWs are mainly contracted for core tasks, and often for heavy-duty work. In order to meet demands for expedient case administration, the supportive aspects of social work are sometimes deprioritised. Permanent staff report that positive effects of the use of TAWs include relief of workload and an influx of new knowledge, whereas negative effects include stagnated work development, deteriorating group dynamics and additional work. Moreover, it is shown that TAWs often reside in the periphery of the organisation and that they typically are contracted on an ad-hoc basis and during times of crisis. It is suggested that the organisational conditions that TAWs are contracted to help remedy paradoxically are unlikely to create the best preconditions for a successful use.