Background: while Hand washing is the simplest strategy to prevent from ventilator-related pneumonias, lots of nurses don’t consider it as an effective measure. This study aimed to determine the effect of educational program on knowledge, attitude, and adherence of critical care unit nurses with respect to hand washing as a preventive strategy against ventilator-related pneumonia.

  Methods: This quasi-experimental study was conducted on 52 critical care unit nurses

  Selected by convenience sampling from two therapeutic and educational center of Hamadan University of Medical Sciences. knowledge, attitude, and adherence of the subjects in respect to hand washing were evaluated both before and one and three months after the intervention by the use of a questionnaire and a checklist. Data was analyzed by SPSS version16 and analytical statistics such as repeated measurements.

  Result : The majority (%80.8) of nurses had not passed any hand washing educational program previously. Both One and three months after the intervention , an increase in the level of knowledge and attitude of the studied subjects was seen (P=0.01).Although the subjects’ adherence to hand washing with alcohol solutions, soap and water was improved, statistical tests were significant only for hand washing with alcohol solutions (P=0.04).

  Conclusion: Short-term and continuous educational programs can enhance knowledge, attitude, and adherence of intensive care unit nurses with respect to hand hygiene as a preventive strategy against ventilator-related pneumonia.