The objective in this study was to evaluate the angiotensin converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism in premature infants with and without respiratory distress within the first 24 hours of life. Totally, 87 premature babies who were followed up in the neonatal unit were included in the study. Of these babies, 41 had respiratory distress, and constituted the patient group. The remaining 46 babies who did not have respiratory distress constituted the control group. Blood samples were obtained from the babies within the first few days of life prior to administration of any blood product. The ACE gene insertion (I) and deletion (D) polymorphism was investigated using polymerase chain reaction method. The I/I polymorphism was frequent in the patient group and the D/D polymorphism was frequent in the control group (p < 0.05). There was no relationship between the ACE gene polymorphism and hospital stay, ventilation or oxygen consumption duration of the patients. In addition, taking into consideration the gestational age, no association was found between ACE gene polymorphism and birth weights of the babies. The I/I genotype was considered a risk factor for pulmonary disorders in neonates as the I/I variant was more frequent in the neonates with respiratory distress than in healthy newborns. The ACE I/I genotype is associated with an increased risk of respiratory disorders among premature infants and the D/D genotype is a protective factor for respiratory disorders, but these infants with ACE D/D genotype might be at risk for the development of cardiovascular disorders later in life.