Background: Controversy exists regarding early reopening and recanalization after successful (complete) coil occlusion of the patent ductus arteriosus (PDA). Methods: Patients with successful PDA coil occlusion were reviewed with regard to PDA size and type, coil size, number of coils, and delivery technique. Follow-up echocardiograms at <24 hours, 6 months, and >12 months were reviewed for residual PDA shunt, left pulmonary artery (LPA) stenosis, and aortic obstruction. Results: Successful coil occlusion was achieved in 94 patients. On the initial (<24 hours) echocardiogram, 76 of 92 (83%) had complete PDA occlusion, 5 of 92 (5%) had mild LPA stenosis, and no patient had aortic obstruction. Follow-up at 6 months was available in 70 patients, 57 with complete occlusion on the initial echocardiogram. PDA reopening was found in 3 of 57 patients (5%). Larger PDA diameter was associated with residual shunt (2.40 ± 0.40 mm versus 1.87 ± 0.53 mm; P <.01). Disagreement between the initial and 6-month echocardiogram was found in 11 of 70 patients (16%). Intermediate follow-up (median, 30 months; range, 12 months to 5.3 years) was available in 46 patients, 38 with complete occlusion on the 6-month echocardiogram. No patient (0 of 38) with a normal echocardiogram at 6 months developed recanalization, LPA stenosis, or aortic obstruction. Conclusion: These data suggest that: (1) routine echocardiography immediately after PDA coil occlusion is unnecessary; (2) early PDA reopening is uncommon; and (3) PDA recanalization does not occur if complete echocardiographic closure is documented 6 months after coil occlusion. Additional follow-up examination in these patients may not be necessary.