We report on a 6-month-old infant (6 Kg/ 64 cm) with perimembranous ventricular septal defect (absent sub-aortic rim, 10 mm left ventricular entry, and 4 and 6 mm right ventricular exists) and successful retrograde closure using an 8x6 mm KONAR-MF™ VSD occluder (Lifetech, China). Immediate and 48 hours post-procedure ultrasounds showed an accurately positioned device and two jets of mild-to-moderate residual shunts. At the 2-week follow-up, the device did not change position and the shunt was stable and intra-prosthetic. The scheduled 3-month follow-up was skipped for familial reasons. The patient came back without alarming symptoms for the regular 6-month follow-up, and the device was found embolised to the left pulmonary artery. The device was retrieved surgically, and the defect was patch-closed with excellent outcomes. There was a pseudoaneurysm involving the tricuspid valve chordae and the device was endothelialized partially on one edge suggesting that embolization occurred somewhere between 3 months and 6 months post-operative. Defects with compromised anatomies should be closed surgically to avoid suboptimal results, especially in small infants.