Increases in the real resources used in hospital care have been an important cause behind rising hospital costs in the United States. Many of these resources have taken the form of new hospital technologies, and this paper begins by reviewing the trends in adoption of new hospital technologies over the years 1950-1974. The resource requirements, costs , and to the extent possible the patient benefits, of two of these technologies are then discussed in more detail: intensive care, a widespread facility with many variations, has been a major contributor to hospital costs; radiotherapy has been characterized by a succession of competing technologies. Regulatory efforts such as certificiate-of-need reviews would be more effective if they viewed hospitals as flexible collections of such technologies-with the costs and patient benefits of each to be weighed separately-rather than primarily in terms of numbers of beds. A national center to collect information on the separate technological functions of hospitals and make it available to interested groups would make a useful contribution to hospital regulation.