PURPOSE: This study aimed to compare cerebral hemispheric volumes between pharmacologic treatment and supportive management of patent ductus arteriosus (PDA). METHODS: The study was conducted retrospectively. The subjects of period 1 group were very low birth weight infants whose PDA were treated with pharmacologic closure. Period 2 group were treated with supportive management. Regional brain volumes measured using magnetic resonance imaging were compared between the two groups. RESULTS: total of 12 infants were included. Their median gestational age was 27⁺⁶ (range: 24⁺¹–31⁺¹) weeks and birth weight was 1,065 g (range: 690–1,380). Between the two groups, there was no difference in Apgar score, incidence of bronchopulmonary dysplasia, necrotizing enterocolitis, and culture proven sepsis. The regional brain volumes such as gray matter (Period 1 group, 76,833 mm³ [55,759–100,388] vs. Period 2 group, 79,870 mm³ [59,957–113,018], P=0.59), white matter (82,993 mm³ [63,130–121,311] vs. 92,576 mm³ [77,200–104,506], P=0.18), cerebrospinal fluid (17,167 mm³ [9,279–22,760] vs. 14,348 mm³ [7,018–27,604], P=0.94), basal ganglia (2,065 mm³ [1,697–2,482] vs. 2,306 mm³ [2,065–3,009], P=0.18), and cerebellum (18,374 mm³ [14,843–24,657] vs. 18,096 mm³ [16,134–23,627], P=0.94) were not different between the two groups. CONCLUSION: Regional brain volumes were not different between pharmacological and conservative treatment in infants with PDA. Further wellcontrolled studies are required to evaluate the advantages or disadvantages of supportive management without pharmacologic treatment of PDA.