Recent studies have shown favorable outcomes for intra-abdominal umbilical vein varices (IUVVs) in term neonates who have no other complications. Little is known, however, about the prognosis of IUVVs in preterm neonates. We encountered a case of IUVV in an extremely low-birth-weight infant who developed severe consumptive coagulopathy after birth. The patient's coagulation test normalized as the varix spontaneously obstructed. Although life-threatening hemorrhagic complications were avoided, a cerebellum hemorrhage was found in the brain magnetic resonance imaging at the term-equivalent age. In a literature survey, coagulopathy was reported in 4 out of 15 infants with IUVVs born before 34 weeks of gestation, including our present case. Preterm infants with IUVVs may develop coagulopathy because of the prematurity of their coagulation–fibrinolysis systems. Attention should be given to the coagulation status of preterm neonates with IUVVs.