This issue of Clinics in Perinatology reviews Healthcare Associated Infections in the Neonatal Intensive Care Unit. Guest Editors Drs. Karen Fairchild and Richard Polin have assembled a panel of expert contributors to pen articles on Epidemiology and Risk Factors for NICU HAI: Genes and Environment; Strategies to Reduce NICU HAI: Line, Tube, and Hand Hygiene;  Candida in the NICU: Pros and Cons of Prophylaxis; MRSA in the NICU; New Concepts of Microbial Translocation in the Neonatal Intestine: Mechanisms and Prevention; Antibiotic Resistance in NICU Pathogens: Mechanisms, Clinical Impact, and Prevention; Biomarkers for LONS: Cytokines and Beyond; Heart Rate Variability: A Novel Physiomarker for Sepsis Detection in the NICU; Ventilator-Associated Pneumonia; Perinatal Infection and Prematurity; and Meningitis in Neonates: Bench to Bedside.