For the prevention of perioperative nosocomial infection, 1) topical mupirocin treatment, 2) tight perioperative glycemic control and 3) immunonutrition are described. A large, prospective, randomized trial showed that the nasal application of mupirocin may effectively reduce postoperative Staphylococcus aureus nosocomial infection in the subgroup of patients who had S. aureus in their nares. Tight glycemic control after surgery, especially in the early period after operation, may also be effective in decreasing postoperative infection. In septic ICU patients, strict glycemic control even reduces ICU and hospital mortality rates. Several specific nutritional substrates such as arginine, omega-3 fatty acids, glutamine, and RNA have been shown to modulate host immune function. Some enteral formulas enriched with such immunonutrients have been commercially available in the USA and in Europe and are now available in Japan. Recent meta-analyses of randomized, controlled trials have shown that the administration of these formulas to elective surgical patients results in a significant reduction in the risk of developing infectious complications by approximately 50% and shortens the overall hospital stay.