Theoretical background: Premature birth is in the focus of research interest as it is the most common perinatal risk endangering the development of children. However, the implications of prematurity for the long-term outcome are far from fully understood. Compromised development of cognitive and executive functions may be underlying academic underachievement in school-age preterm children. Aim: to assess the school-age outcomes of Hungarian VLBW/ELBW preterm children in basic cognitive abilities and executive function as compared to typically developing, full-term children as well as to investigate the background of individual differences. Method: 54 preterm children (27 ELBW, 27 VLBW) and a matched group of 27 healthy full-term children, aged 9–10 years, were tested using the Wechsler Intelligence Scales for Children (WISC-IV), the Corsi Block Tapping Task (digital version) for measuring spatial–visual working memory and the Wisconsin Card Sorting Test (WCST, digital version) for testing cognitive flexibility. As background variables perinatal and socioeconomic factors were entered in the analysis. Results: In each measure of the WISC-IV all three groups performed in the normal range. The ELBW children displayed certain developmental lags. They scored significantly lower in the Full-Scale IQ and the Processing Speed than the other two groups, and in the Perceptual Reasoning and one measure of spatial–visual working memory as compared to the non-risk comparison group. Perinatal complications and maternal education were related to the outcome. Conclusions: With the improved perinatal care preterm children have fair chances for good developmental outcomes. However, the individual variations are great and various perinatal and social factors may hamper the development of cognitive and executive functions. A birthweight below 1000 grams is a notable risk, particularly if combined with perinatal complications.