OBJECTIVE: To report initial experience with a new occlusion device for native and residual patent ductus arteriosus. DESIGN: Descriptive study of consecutive non-randomised patients undergoing a new method of patent ductus arteriosus closure with detachable coils. SETTING: Tertiary centres for paediatric cardiology. PATIENTS: 71 consecutive patients, aged 1.2-22 years, with a patent ductus arteriosus (PDA) underwent elective transcatheter closure. 45 had native PDAs (group A) with a minimum diameter of 1.0 mm-5.0 mm (median 2.0 mm). A further 26 had undergone one or more previous occlusion attempts (group B). INTERVENTIONS: A total of 133 detachable (Cook) spring coils were successfully implanted in 70 patients. The procedure was performed transvenously in 51 patients, retrograde arterially in 13, and by both routes in a further 6 patients. One 5 mm coil migrated but was successfully retrieved. MAIN OUTCOME MEASURES: In group A colour flow Doppler echocardiography showed that complete occlusion was achieved in 40/45 (89%) at 24 hours, 41/45 (91%) at 1 month, and 44/45 (98%) by 6 months post procedure. Occlusion rates in residual PDAs were 22/25 (88%) occluded at 24 hours, 23/25 (92%) at 1 month, and 24/25 (96%) at 6 months follow up. CONCLUSIONS: Transcatheter occlusion using detachable (Cook) spring coils is a safe and effective alternative to presently available devices. The delivery system allows full retrieval of the coil until a satisfactory position is obtained.