We reported transcatheter closure of gigantic persistent ductus arteriosus (PDA) complicated by severe pulmonary hypertension (PH) using a custom-made PDA occluder. A 19-year-old lady weighing 45 kg visited to our Heart Saving Project in Mongolia with a chief complaint of shortness of breath. Contrast CT scan showed ellipsoidal section of PDA whose long axis being 28 mm, and the short axis of 21 mm. A custom-made PDA occluder, whose retention skirt, the aortic side, and the pulmonic side diameter of the body were 54, 36, 34 mm, respectively, was successfully deployed using 14-Fr sheath. Pulmonary pressure decreased around a half compared to before closure. A custom-made duct occluder could be a reasonable and cost-effective choice for transcatheter closure of gigantic PDA complicated by severe PH. © 2015 Wiley Periodicals, Inc.