Objective: We report the efficacy of new Amplatzer Duct Occluder (ADO II) in young children with hemodynamically significant small to moderate Patent Ductus Arteriosus (PDA) from October to December 2008. Methods: A total of 13 children diagnosed to have PDA (diameter <5mm) were included in the study. The average age of the children was 18 ± 15.06 months (4 to 48 months). The body weight was 7.9 ± 2.31 kg (3.5 to 11 kg). There were 11 females and 2 males. All children were thoroughly evaluated clinically and echocardiographically. The procedure was done under general anesthesia after obtaining informed consent. Descending thoracic aortic angiogram was done in lateral view in all cases and RAO view in selected cases. PDA diameter, length and ampulla were measured angiographically and correlated with echocardiogram. The device size was selected 1.5 to 2 mm higher than the narrowest PDA diameter whereas the length was chosen 4mm and 6mm for the duct length lesser and greater than 4mm respectively. The descending aortic and the pulmonary artery angiogram were done in all cases before final deployment. Results: The procedure was successful in all children. There were no procedure related complications. There was mild residual leak in one child at 24 hrs which disappeared at 72 hrs. We conclude that ADO II is safe and effective in closing small to moderate PDA in young children using 4f and 5f delivery systems.