This review covers the recent studies that have served to further our understanding of the nature of the relationship between perioperative hyperglycemia and nosocomial infection. On the one hand hyperglycemia can be a consequence of the systemic inflammatory response, and can serve as a marker of the severity of stress and the degree of immunocompetence resulting from infection or injury. Strong evidence is, however, emerging that hyperglycemia in the perioperative period can also be a significant risk factor for the development of nosocomial infection.