Background: Ventilator-associated pneumonia (VAP) is a very common nosocomial infection in intensive care units (ICU) with subsequent increase in morbidity, mortality and cost. Objective: Toestimate the effect of strict compliance of VAP bundle on decreasing VAP rate per 1,000 ventilator days. Methodology: A prospective study was done in adult ICU at Al–Hayat Hospital, Jeddah, KSA; between January 2013 and April 2015. During the period of January to March 2013, ICU staff nurses were educated and made aware about the use of ventilator bundle in helping to prevent this infection. One hundred sixty four patients with age ranged between 33-60 years old were intubated and ventilated for more than two days were suspected to have VAP. Cases were divided into two groups; the first group (84 patients) included all patients admitted to ICU, intubated and ventilated for more than two days with incomplete compliance with VAP bundle (missed one or more components of VAP bundle), the second group included 80 patients with strict compliance of VAP prevention bundle. Patient (s) who are expired within 48 hrs of admission, transferred to tertiary care unit within 48hrs, diagnosed with pulmonary embolism or had gastrointestinal bleeding prior to admission were excluded from this study. Results: There was no significant difference between cases with incomplete application or strict application of VAP bundle as regard age, sex distribution or cause (s) of ICU. On the other hand, there was a significant decreased VAP% in cases with strict application of VAP bundle (1.3%) when compared to patients with incomplete VAP bundle application (9.5%). In addition, the rate of VAP cases /1000 ventilator days significantly decreased from 13.6/1000 (in cases with incomplete VAP bundle application) to 3.1/1000 (in cases with strict application of VAP bundle). Also, there was significant decrease as regard the mean duration of ventilation; from 7±091dayes in cases with incomplete VAP bundle application to 4±0.75 days in cases with strict application of VAP bundle. In addition, the mean length of ICU stay was significantly shortened from 10.42±1.71 days in cases with incomplete application of VAP bundle to 7.25±1.08 days in cases with strict application of VAP bundle. Finally ICU mortality was significantly reduced from 23.8% in cases with incomplete VAP bundle application to 7.5% in cases with strict application of VAP bundle. Conclusion: Theresults of the study revealed efficacy of strict implementation of VAP prevention bundle in reducing incidence of VAP/1000 ventilator days, decreasing duration of ventilation, shortening length of stay and decreasing ICU mortality rate related to VAP. Thus, it is advocated to continue strict adherence to these bundle.