Although much is now known about the effects of intrauterine growth retardation (IUGR) on children born SGA with regard to anthropometric and biochemical parameters and their treatment, there are still many gaps associated with its impact on neurocognitive functions. In our experience published several years ago, IUGR has a negative effect on neurocognitive development, regardless of whether these children showed evidence of catch-up growth or not or of the socio-economic conditions that might contribute to the situation. We have now accumulated a large number of cases, many of whom have been followed longitudinally, some for up to 7 years, many having been treated with GH from the time when this therapy was first approved by the EMA. Apart from the cases mentioned, other confounding factors such as gestational age, Apgar score, neonatal comorbidity and the possible effects of GH treatment have also been included. In addition and using our own reference standards, we now present our experience, which confirms what we had already noted in the past, that IUGR is in itself a condition that often causes psychomotorintellectual impairment, may be extremely severe and tends to worsen. This negative impact of IUGR on neurocognitive development does not depend on how the child grows,spontaneous growth is better and when growth is not altered by GH therapy. Later studies will be able to confirm whether early treatment with GH throughout the 2nd year of life, or an early specific stimulation programme, or the sum of both, can improve the neurocognitive development of these children. IUGR prevention, acting on causal factors that are partly avoidable such as smoking, working conditions and stress during pregnancy (see the corresponding article in this supplement) proves once again to be the best way to stop this negative impact on the IQ of many children born SGA.