Postoperative fever can be defined by a temperature greater than 38 °C on 2 consecutive postoperative days, or higher than 39 °C once. Causes of postoperative fever may be either infectious or noninfectious. The inflammatory response from tissue trauma during surgery results in cytokine release including IL-1, TNF-α, IL-6, and INF-γ which may cause fever and systemic inflammatory response syndrome (SIRS). Index of suspicion for infectious etiologies must increase as time after surgery increases (72 h or more postoperatively). The differential may be broad and the workup should take this into consideration; however, the focus should appropriately be on the index operation (where were the hands of the surgeon and how might that explain the scenario?). Understand the details of what case was performed, and was anything out of the ordinary? Was it emergent, urgent, or elective? What was the indication? Were there any complications or what might be anticipated postoperative occurrences? (Reminder: The occurrence of a complication is not a failure; the exam is designed to assess how the examinee handles occurrences and thinks through scenarios.) What tubes, lines, or drains were used in the case? What was left after the case, for how long, and for what purpose? Where do the drains sit and what is the expected effluent? If the fever is symptomatic, find out what symptoms the patient exhibits and tailor the workup to the patient. Avoid a pure shotgun approach and the tendency to pan culture, but rather critically think what might be causing the symptom and act accordingly.