Among the many factors affecting the hospital utilization rate in a region, little attention has been given to the supply of physicians. Characteristics of patients have been studied as well as policies of hospitals and practices of physicians. This paper explores the relationship of the physician-population ratio to the hospital admission rate in the 48 continental states of the United States. After making statistical corrections for insurance coverage and the available supply of hospital beds, it was found that below a threshold supply of 110 physicians per 100,000, the rate of hospital admissions tends to go up as the supply of physicians goes down. Possible explanations for this are explored. Rising hospital admission rates, therefore, may be partially due to the existing lag in the output of physicians. The implications of this for medical education are discussed.