Clinicians and researchers are linking elevated glucose levels with potential infectious outcomes. Physiologic processes to fight foreign agents are potentially impaired during periods of hyperglycemia. Some of these responses, such as immune function and the inflammatory response, are impaired when they are needed most, such as during the recovery from surgical procedures. Investigators have demonstrated the importance of control of serum glucose postoperatively. Outcomes are improved when tighter glycemic control is practiced. The current literature challenges practitioners to become more cognizant of serum glucose in surgical patients and patients who are critically ill, implementing protocols to gain tighter control of serum glucose in any patient may be appropriate. Further investigation of glycemic control in surgical and other populations will reinforce research findings in this area. Studies should be performed on surgical patients who are particularly vulnerable to DM, glycemic alterations, and postoperative infections, such as patients undergoing peripheral vascular surgery. Further investigations are also needed on the role of hyperglycemia and outcomes in nondiabetic individuals, and on the similarities or differences in glycemic control in types 1 and 2 DM. To increase the generalizability of the study findings, definitions used across studies, such as the type of diabetes, should be standardized. When these studies determine optimal glycemic control practices in a variety of patient populations, clinicians will be able to determine the best practice guidelines to optimize patient care and limit adverse infectious outcomes.