Background: Health services that operate 7 days per week are under pressure to show the increased cost of providing weekend services can be measured in improved patient outcomes. The evidence for weekend allied health services in acute medical and surgical wards is weak and there is wide variation between the services offered at different hospitals. Methods: This qualitative study was undertaken during a multi-site stepped wedge randomised controlled trial involving twelve acute medical and surgical wards from two Australian hospitals, in which weekend allied health services were removed before being reinstated with a stakeholder driven model. In-depth interviews were conducted with twenty-two staff responsible for managing weekend services at the involved hospitals. Participants were asked about their perceptions of the advantages and disadvantages of providing a weekend allied health service. Results: Managers perceive the services improve patient flow and quality of care and reduce adverse incidents, such as falls and intensive care admissions. They also highlighted the challenges involved in planning, staffing and managing these services and the uncertainties about how to provide it most effectively. Conclusions: Rising healthcare costs provide opportunity for public and professional debate about the most effective way of providing weekend allied health care services, particularly when health services provide limited other weekend services. Some managers perceived weekend allied health services to improve patient quality of care, but without studies which show these services on acute medical and surgical wards clearly change patient outcomes or provide health economic gains, these resources may need to be redirected. The resources may be better spent in areas with clear evidence to show the addition of weekend allied health services improves patient outcomes, such as on acute assess units and rehabilitation wards.