A multidisciplinary group was formed to develop strategies to reduce ventilator-associated lower respiratory tract infections (LRI) in an intensive care unit (ICU) of a 540-bed acute care teaching medical center. The group process was facilitated by the Infection Director and the quality management specialist. The group was made of medical, nursing, and respiratory therapy staff. Quality improvement techniques were used to define the process of care for ventilated patients in the ICU. "State of the art" care was defined after a literature review and brainstorming sessions. Current practice and new concepts were then forged into a realistic protocol for the ICU. The resulting protocol was introduced into the ICU in May 1992. The information was communicated to Respiratory Therapy and ICU staff in writing and at department meetings. After a 4-month introductory period and learning curve process, a decrease in the endemic rate of ventilator-associated LRI was reduced in the fourth quarter of 1992. The mean 1993 LRI rate was 21 LRI/1000 ventilator days versus 26 LRI/1000 ventilator days in 1992 before protocol implementation. This equates to 18 LRI prevented in 1993. This represents a savings of $126,000. There was a significant decrease in the process variation of the monthly mean LRI/1000 ventilator days in 1993 from 1992. To date, there continues to be improvement with a mean of 16 LRI/1000 ventilator days reported in 1994. The ICU staff developed a multidisciplinary process evaluation and monitored staff implementation of the protocol over time. The results of the evaluation were used as feedback to measure protocol implementation. This was found to improve compliance with the protocol. Both the process (care of ventilated patients) and the outcome (number of LRI) have been improved through use of continuous quality improvement concepts and transdisciplinary interventions.