Perioperative nutrition is a vitally important yet often overlooked aspect of surgical care. Significant disparity exists between evidenced-based recommendations and practices encouraged by traditional surgical teaching. The metabolic response to surgical stress is complex. Poor nutrition has been demonstrated to correlate with adverse surgical outcomes. Perioperative nutrition encompasses preoperative, intraoperative, and postoperative care. Preoperative nutritional assessment identifies at-risk patients who benefit from supplementation before surgery. Prehabilitation seeks to prepare patients for the impending surgical stress. Immunonutrition seems to provide a benefit, although its precise mechanisms are unknown. This article provides a review of the current state of perioperative nutrition.