Objective: To examine the effects that a physician's knowledge of a patient's socioeconomic status or profession has on clinical decision making in an outpatient setting. Methods: We mailed a survey to all 336 members of the Academy of Medicine of Cleveland who are general internists, family practitioners, or general practitioners. Physicians were randomized before the initial mailing to receive one of the two questionnaires. Physicians in group A were given two simulated clinical scenarios in which the socioeconomic status or profession of the patient was identified, followed by management options. Physicians in group B were given the same scenarios without any suggestion of the patient's profession or social standing. Outcomes that reflect decision making, intensiveness of evaluation, and treatment course were compared for the two groups. Data were analyzed using t tests and χ2. After Bonferroni correction, a P≤.01 was considered significant. Results: The response rate was 60%. For clinical scenario 1, no difference was noted in the number of tests ordered. However, physicians in group A responding to clinical scenario 2 ordered more total tests than did physicians in group B (P=.03), including complete blood cell counts (45% vs 29%, P=.01). In both scenarios, earlier follow-up visits were scheduled by physicians in group A compared with those in group B (P=.01). Conclusion: Our results do not support findings by other investigators that more tests are ordered when physicians perceive their patients to be of higher socioeconomic status. Intensity of follow-up, however, was greater when physicians believed the patient was in a more prominent profession or was of higher socioeconomic status.