The evidence continues to strengthen our understanding that improved glycemic control with the use of insulin therapy may significantly improve morbidity and mortality in hospitalized patients with hyperglycemia, with or without a previous diagnosis of diabetes. However, many questions remain concerning the impact and relative contributions of blood glucose and insulin per se. Nevertheless, the publication of numerous and consistent studies have made it clear that the topic of glycemic management in the hospital requires a larger priority among clinicians caring for these patients. The recently published guidelines by the American Association of Clinical Endocrinologists are the first formal recommendations on this topic,but national guidelines for blood glucose levels cannot take into account all of the different challenges facing different hospitals. This suggests that each institution will require individualization of protocols even though the ultimate metabolic goals are identical. Furthermore, it is not realistic to expect those unfamiliar with diabetes therapy to appreciate all of the nuances and vagaries of insulin treatment. Like any medical treatment, a significant amount of time will need to be invested by the providers involved with the.care of these patients before a mastery of the therapy can be achieved. Nevertheless, because the rewards to our patients can be significant, we need to strive to improve the systems where we work. Individual clinicians with vast experience in diabetes care cannot be successful for the inpatient with diabetes unless the hospital has systems in place to effectively and efficiently facilitate the management of the metabolic needs of this population. The main challenge now is the safe and effective implementation of these guidelines in both small and large hospitals given the limited level of re-sources available in today's medical environment. Therefore, our single most important recommendation is to ensure that all clinicians involved in the management of these patients are in agreement about general philosophies of diabetes management. We would recommend that there are "champions" for each discipline: endocrinology, cardiology, anesthesiology, surgery, nursing,and pharmacy, all of which have developed hospital-specific guidelines for glycemic management. These recommendations can be slowly adapted, one unit at a time, until the entire hospital has transitioned to a more "diabetes-friendly" environment. The ultimate goal of well-controlled glycemia with minimal hypoglycemia should be possible for most hospitals, and we hope this review will assist clinicians in achieving this objective. We await additional outcome research with carefully controlled studies to confirm the value of these recommendations at different levels of glycemic control. We believe that we can already state with confidence that the preliminary evidence shows that, like outpatient diabetes management,metabolic control matters during acute illness.