Aims & Objectives: To determine risk factors and outcomes for prolonged invasive mechanical ventilation (pIMV) in infants admitted to pediatric ICU (PICU) due to acute respiratory failure (ARF). Methods: Retrospective analysis using prospectively collected data within LARed Network ARF registry (33 hospitals, 8 countries). All PICU encounters in children younger than 2yo which needed invasive MV (IMV) from May 2017 to October 2019 were included. We defined pIMV as the closest day to the p75 percentile. Demographics, etiology, clinical data and discharge outcomes, late mortality (after 5th day) and PICU acquired morbidity measured with Functional Status Score (FSS). Variables were described and expressed as median (p25, p75) or frequencies (percentage) and adjusted through mixed logistic regression model. Results: Final analysis included 1140 children. Duration of IMV was 111 hours (44, 187). A cut off for pIMV was set at 8 days. Risk factors identified for pIMV were age (OR: 0.96, 0.93-0.99), bronchopulmonary dysplasia (BPD) (OR: 1.96, 1.15-3.35) and home O2 dependency (OR: 2.36, 1.11-5.00). pIMV group had more IMV related complications (OR: 5.13, 3.17-8.30), healthcare-acquired infections (OR: 5.44, 3.11-9.53), and longer PICU length of stay (LOS) (OR: 1.14, 1.11-1.17). Although overall and late mortality were initially not significantly different, when we combine late mortality and new morbidity (change in FSS >3 points), they became significant (OR: 2.55, 1.48-4.37). Conclusions: Age, BPD and O2 dependency are risk factors for pIMV. pIMV was associated with worst patient important outcomes. Reducing IMV time should be a quality improvement metric in our network.