The somatic growth of a regional birth cohort of 351 preterm infants was followed during their first two years. The measurements of weight, height, head and thorax circumferences took place at the well-baby clinics run by public health nurses at 3, 6, 12, 18 and 24 months of conceptional age. The growth of the preterm infants was compared with that of their term peers with uncomplicated course of pregnancy, labour, delivery and neonatal period. The preterm infants without intrauterine growth retardation caught up the term control infants by three months of conceptional age. The preterm small-for-gestational age infants remained smaller than the preterm appropriate-for-gestational age or the control infants in all measures throughout their first two years of life. Birth weight rather than gestational age predicted the growth outcome in preterm infants. Moderate or severe respiratory distress had no impact on the future growth of the infants in the present material. Prematurity as such does not seem to influence the growth of preterm infants.