Regional integration of hospital services was widely discussed by policy-makers in interwar Britain, although historians remain divided on the strength of the consensus in favour of planning. The aim of this article is to explore the forces at work in the comparatively early reorganization of services in the Scottish city of Aberdeen. This included the relocation of its medical school and main hospitals, the conversion of its poor law accommodation to a municipal hospital, and the joint agreements made with neighbouring authorities to provide public health services. In part these were expressions of the shared interest of the voluntary hospital leadership, public health officials, and the university, in the efficient harnessing of science to the demands of mass medicine. However, the `Aberdeen experiment' also owed much to the ideas and assertiveness of three successive Medical Officers of Health. These men were closely associated with the Scottish Board of Health (later Department of Health for Scotland) and their work provides an insight into the development of distinctive Scottish health care arrangements prior to the establishment of the National Health Service.