BACKGROUND: The association between early antibiotic administration and outcomes remains controversial in patients hospitalized for community-acquired pneumonia. METHODS: We performed a secondary analysis of a randomized controlled trial comparing two antibiotic treatment strategies for patients hospitalized for moderately severe CAP. The univariate and multivariate associations between time to antibiotic administration (TTA) and time to clinical stability were assessed using a Cox proportional hazard model. Secondary outcomes were death, intensive care unit admission and hospital readmission up to 90days.