Wolf-Hirschhorn syndrome (WHS) is characterized by multiple malformations as well as mental and developmental defects resulting from the absence of a distal segment of the short arm of chromosome 4. We experienced an extremely low birthweight infant with WHS. The male infant (birthweight 934 g) was born at 31 weeks' gestation by cesarean section due to intrauterine growth restriction and presented with the typical WHS phenotype. Chromosomal analysis showed a deletion: 46,XY,del(4)(p15.3 p16). Although the patient's respiratory distress syndrome resolved favourably and his subsequent condition was also stable, he had unusually severe retinopathy of prematurity and periventricular leukomalacia. We suppose that these severe complications were associated with not only prematurity but also with latent structural fragility due to WHS. Herein, we discuss the prenatal detection of WHS and the optimal timing of delivery.