Background: In this review, we describe the growth of (very) preterm infants or (very) low-birth-weight infants from birth until adulthood. Methods: A systematic analysis of growth of these infants is thwarted by different definitions (classification by gestational age or birth weight) used in the literature. Results: The early postnatal period of these individuals is almost invariably characterized by substantial growth failure. In the majority of preterm infants this is followed by a period of catch-up growth, which starts in early infancy and usually stops at 2-3 years of age, although in some cases it may continue into adolescence. Catch-up growth is usually incomplete, so that infants born preterm remain shorter and lighter than term-born peers during childhood, adolescence, and adulthood. Disproportionate catch-up growth in height and weight may lead to an altered body composition in adulthood, especially in females. Conclusion: Though early catch-up growth has shown to be beneficial for neurodevelopmental outcome, it is also associated with adverse metabolic consequences in adulthood. As the first generation of (very) preterm infants is now reaching young adulthood, future follow-up studies on these effects are warranted. Copyright © 2008 S. Karger AG.