In this article, we have shown that almost all "routine" laboratory tests before surgery have limited clinical value. Clinicians should order only a small number of routine tests based on age as noted in Table 13. Selective use of other preoperative tests should be based on history and physical examination findings that identify subgroups of patients who are more likely to have abnormal results. In general, clinicians should order tests only if the outcome of an abnormal test will influence management. When an abnormal test results from such testing, it is critical that physicians document their thinking about the result. Most routine preoperative tests are neither expensive nor risky. For this reason, clinicians can have a low threshold for ordering these tests in patients for whom the frequency of abnormalities is increased compared with a healthy population. We believe that physicians should not be criticized for selective test ordering before surgery. Physicians and institutions recommending routine preoperative testing for all patients provide no clinical value to their patients at considerable cost.