The proportion of infants born between 340 and 366 weeks’ gestation, or “late-preterm” infants is increasing. Because they are often the size and weight of some term infants, they may be treated by parents, caregivers and health professionals as developmentally mature and at low risk of morbidity. Their increasing incidence may reflect increased use of reproductive technologies and thus multifetal pregnancies or increased obstetric surveillance and intervention so that fetuses at risk of stillbirth from growth restriction, fetal anomalies and intrapartum asphyxia are identified and delivered earlier. The last 6 weeks of gestation represent a critical period of growth and development of the fetal brain and lungs, and of other systems. There is accumulating evidence of higher risks for health complications in these infants, including serious morbidity and a threefold higher infant mortality rate compared with term infants. This information is of critical importance because of its scientific merits and practical implications. However, it warrants a critical and balanced review, given the apparent overall uncomplicated outcome for the majority of LP infants. There is increasing evidence of long-term adverse neurodevelopmental and respiratory outcomes, with prenatal, neonatal, developmental, and environmental causes for these increased morbidities. This presentation will explore evidence supporting the practical implications for perinatal and neonatal care during infancy and childhood.