Percutaneous catheter closure of patent ductus arteriosus (PDA) is difficult when the ductus is large and long or shows calcification. We created a patient-specific 3-dimensional (3D) model for PDA, with which we simulated device deployment, thereby selecting the device/size in a patient-by-patient manner. We assessed whether this 3D model is effective for catheter PDA closure. The 3D model was created in this institute, requiring 3 days and 90 US dollars. After its introduction, 7 consecutive patients (the study group) with severe PDA underwent closure with the aid of the 3D model. The control group consisted of 4 patients before 3D-model introduction, with all having severe PDA: the requirement of computed tomography was considered a criterion of severe or difficult-procedure-requiring PDA. In all study group patients, the devices/sizes could be pre-selected based on the simulation, whereas devices were changed during the procedure in 2 of 4 in the control group. In the study group, compared with the control group, the fluoroscopic (median 31 [interquartile range of 16-42] versus 39 [19-71] minutes, respectively) and total procedural times (median 107 [interquartile range 67-114] versus 124 [78-184] minutes, respectively) were shorter. A questionnaire confirmed the doctors' understanding of the procedure. This 3D model may be effective for percutaneous catheter closure of PDA. This may be especially true in cases of severe or difficult-procedure-requiring PDA.