PURPOSE: To determine changes in usage of radiologic services between 1980 and 1990. MATERIALS AND METHODS: Complete data were obtained from 107 (42%) hospitals and incomplete data from eight (3%) (total survey response rate, 45%). Information was requested about the number of general radiologic examinations; specific modalities of computed tomography (CT), magnetic resonance (MR) imaging, nuclear medicine, and ultrasonography (US); and numbers of CT, MR imaging, and US machines. RESULTS: The number of general radiologic examinations in hospitals increased from approximately 126 million to 179 million (>42%); for CT, from 3.6 million to 13.3 million; nuclear medicine, from 6.4 million to 7.4 million; and US, from 4.3 million to 11.8 million. MR imaging examinations performed during 1990 were estimated at 1.8 million. CONCLUSION: The number of radiologic examinations performed in U.S. hospitals increased by 30%-60% between 1980 and 1990, mainly due to increased usage of CT, MR imaging, and US.