['Any delay in adequate antibiotic treatment compromises the outcome of ventilator-associated pneumonia (VAP). However, the diagnosis and optimal treatment of VAP remain a challenge for intensivists. We assessed the potential impact of using results of routine weekly endotracheal aspirate (EA) cultures to guide initial antibiotic treatment for VAP.', 'Retrospective analysis of prospectively collected data in a medical-surgical intensive care unit (ICU) of a university hospital.', 'We studied 113 VAP episodes and evaluated the concordance between the latest EA and the broncho-alveolar lavage (BAL). We stratified patients into three groups: concordant EA-BAL (concordant group), discordant EA-BAL (discordant group) and EA not performed group. We then compared the adequacy of the antibiotic prescribed initially and outcomes between the three groups.', 'Ninety assessable EA-BAL samples were evaluated. When guided by EA, the initial antibiotic regimen was adequate in 85% of situations, a proportion significantly superior (P < 0.05) to that resulting from application of the ATS guidelines (73%). When clinicians did not have a pre-VAP EA to guide their treatment (EA not performed group), only 61% of treatments were adequate. No significant difference was observed between the three groups for length of mechanical ventilation, length of ICU stay, nonpulmonary nosocomial infections and mortality.'] Does previous endotracheal aspirate allow guiding the initial treatment of ventilator-associated pneumonia?