Low birthweight children are at risk for motor, language and cognitive delay in early childhood. The aim of the present study is the examination of cognitive skill development among 4-year-old preterm and low birthweight children in relation to demographical and perinatal variables. We utilized the Wechsler Preschool Primary Scales of Intelligence-IV for measuring IQ. 33.3% of the children performed in the ranges of below average (IQ<90). We found that perinatal and neonatal risk factors for lower cognitive functioning are birthweight (especially less than 1000 grams), and bronchopulmonary dysplasia, retinopathy of prematurity, or intraventricular haemorrhage after birth. We also identified demographical risk factors, such as lower maternal education, lower socioeconomic status, and Roma ethnicity. In conclusion it is crucial to emphasize, that early intervention programmes for cognitive development should consider implementing the education of the parents to broaden their and their children's perspectives in life. Another important task is monitoring the development of low birthweight children with neonatal chronic diseases and providing them with the earliest interventions to nurture cognitive skill development which may promote the optimal development of academic skills and prevent delays.