The 2015 William H. Harridge lecture of the 2015 Midwest Surgical Association concentrated on the evolution and performance characteristics of nonoperative management of even severe renal injury. One of the first mentions of nonoperative renal trauma occurs after World War II. Since that time through the early 2000s, only 1 or fewer papers per year appeared in the literature. The mid-2000s had an explosion of interest and publications on the subject, resulting in our modern understanding of the principles. The principles of nonoperative management are as follows: (1) operate immediately if the patient is bleeding to death; (2) observe initially, but step in with metered responses as necessary; (3) use ureteral stents for symptomatic or growing urinoma; (4) use angioembolization for nonemergent bleeding or for urgent bleeding if your center can manage this; and (5) do open surgery when needed (not “never”).