<i>Background:</i> Major defects in the <i>IGF1</i> gene are associated with severely reduced cranial and linear growth. The association between <i>IGF1</i> promoter polymorphisms and growth is uncertain. <i>Aims:</i> To test the effect of the <i>IGF1</i> 192-bp allele on cranial and linear growth and body mass index (BMI) from birth until age 5 years, and on IQ and serum IGF-1 at age 19 years. <i>Methods:</i> In a birth cohort, including 285 individuals born at a gestational age <32 weeks from the Project On Preterm and Small-for-gestational age infants (POPS), cohort anthropometric measurements were analyzed. At age 19 years <i>IGF1 </i>genotype, serum IGF-1 level and IQ were determined. Regression analyses were performed with mixed models. <i>Results:</i> Homozygotes for the 192-bp allele had a slower cranial growth from birth until age 5 years, and a tendency towards less brain sparing and a slower linear growth compared to the other 2 genotype groups. <i>IGF1 </i>genotype was not associated with IQ or BMI development. Head circumference SDS at age 5 years was positively associated with IQ at age 19 years. <i>Conclusion:</i> Homozygosity for the <i>IGF1</i> 192-bp allele is associated with a slower cranial growth from birth until age 5 years in individuals born very preterm.