The purpose of this study is to determine the influence of medical school, teaching hospital, and specialization on physicians' use of clinical and technical resources. The universe of the study consists of 34 internists practicing in the prepaid group practice setting of Kaiser in Portland, Oregon. The data reported here show that physicians trained in medical schools and hospitals with a scientific medical orientation generally use fewer such resources than other physicians. However, under conditions of uncertainty, that is, when diagnosis is unknown, they tend to use more services. In other words, these physicians are conservative in their use of resources when ambiguity is low, and liberal when ambiguity increases. Graduates of the more scientifically oriented institutions seem therefore more flexible in adjusting to the demands of the disease situation.