Objectives . This report summarizes our experience with the use of occluding spring coils to close the small patent ductus arteriosus. Background . Several patent ductus arteriosus occluders (most notably the Rashkind device) have been developed and studied. Occluding spring coils have been used to close abnormal vessels and vascular connections. We previously reported the use of occluding spring coils to close the small patent ductus arteriosus in a small group of patients. This report describes our series of patients having patent ductus arteriosus closure with occluding spring coils. Methods . Between June 1990 and June 1993, 30 patients underwent cardiac catheterization to have patent ductus arteriosus closure by occluding spring coils. Selection criteria were age >6 months and narrowest patent ductus arteriosus internal dimension ⪯3.0 mm by color flow imaging. Definitive selection was based on review of aortograms performed at catheterization. A 5.2F coronary catheter was used to deliver one or two standard occluding spring coils. A loop was delivered in the main pulmonary artery, and the remainder of the coil was delivered across the patent ductus arteriosus and into the aortic diverticulum. Patent ductus arteriosus closure was confirmed by aortography or color flow imaging, or both. Follow-up after coil placement occurred at 6 weeks and 6 months and included two-view chest radiography, echocardiography and color flow imaging. Results . Of the 30 patients, 29 had successful implantation by one (27 patients) or two (2 patients) occluding spring coils. Of these 29 patients, 19 had a clinically apparent and 10 had a silent patent ductus arteriosus. Average ductus minimal internal dimension was 1.7 mm (range 1.0 to 3.0). Complete closure of the ductus was confirmed in 27 patients by aortography or color flow imaging or both (in 24 within 4 h, in 2 after 6 weeks and in 1 after 6 months). Six weeks after implantation, two patients had a tiny residual patent ductus arteriosus noted on color flow imaging. One patient did not have successful implantation. This patient had a 3.2-mm ductus, and two coils migrated to the distal left pulmonary artery and could not be retrieved. There were no deaths or any significant complications noted during early or late follow-up in these patients. Conclusions . Occluding spring coils may have additional application in closing the small patent ductus arteriosus.