In our intensive care unit we monitored infection in 228 patients who underwent percutaneous dilatational tracheostomy (PDT). In the first phase of the study 128 PDTs were performed during a 33-month period and there were 41 infection complications (nosocomial pneumonia, bacteremia with sepsis, and septic shock) in the perioperative period (immediately prior to and for 5 days after PDT). A significant risk factor among patients with nosocomial pneumonia was empirical administration of inappropriate antibiotics, compared to appropriate antibiotics (34% versus 4%, p < 0.001). In the second phase of the study (a 30-month period), a simple antibiotics protocol was prospectively applied to 100 PDT patients. The protocol virtually eliminated inappropriate antibiotic drug use immediately prior to PDT and contributed to a significant reduction in perioperative infective complications (pre-protocol 32% versus protocol 11%, p < 0.001).