Prematurity and intra-uterine growth restriction (IUGR) are risk factors for long-term poor neurodevelopmental outcomes and are associated with reductions in regional brain volumes. In this study, the aim was to determine the possible role of 3-D ultrasonography (3-DUS) volumes of whole brain, thalamus, frontal cortex and cerebellum, measured at postnatal days 30–40, as early predictors of long-term risk for neurobehavioral disorders. To this purpose, a heterogeneous population of full-term, preterm, IUGR and preterm IUGR (pre-IUGR) born individuals (n = 334), characterized by gestational age and birth weight in the ranges 24–41 wk and 860–4000 g, respectively, was followed from postnatal days 30–40 to the second year of life. At enrollment, brain volumes were measured using 3-DUS, whereas neurodevelopment was assessed at 2 y using the Griffiths III test. Cerebral volumes were strictly and significantly lower in infants characterized by a negative outcome and had excellent diagnostic accuracy. The 3-DUS volume of whole brain, thalamus, frontal cortex or cerebellum may be an early predictor of neonates at major risk for neurobehavioral disorders in later life. © 2021 World Federation for Ultrasound in Medicine & Biology