Introduction: Ventilator-associated pneumonia (VAP) is one of the most popular nosocomial infections in the intensive care units and the nurse’s role in preventing it is very important. The aim of this study was to compare the effect of two methods of face to face training and work- shop clinical guidelines in prevention of VAP. Methods: In this experimental randomized clinical trial, the knowledge and practice of nurses in ICUs were studied in two groups: face to face training (35 nurses) and workshops (40 nurses) by using clinical guidelines in prevention of VAP in one of the hospitals of Shiraz University of Medical Sciences. The level of knowledge and practice in each group was assessed by selfreport questionnaire, knowledge questionnaire and also direct observation of practice, before and after training. Data were analyzed with descriptive statistics, paired t-test, independent t-test, McNemar test, Fisher’s exact, sign and Chi-square test, using SPSS 14. Results: This study demonstrated that both methods of face to face training and workshop were very effective. The incidence of inappropriate pressure of cuff in the tracheal tubes and tracheostomy tubes was significantly reduced after training (p=0.001). But, by comparison of these two methods and the relationship between the variables revealed that no significant difference was found between the two groups of face to face training and workshop. Conclusion: Training the nurses is highly effective in preventing VAP, particularly for appropriate cuff pressure, suctioning and disinfecting hands.