The purpose of this article is to present the immediate and short-term results of the international registry of transcatheter closure of patent ductus arteriosus (PDA) using the Amplatzer duct occluder (ADO). Three hundred sixteen patients (221 females) in various centers with clinical and/or echocardiographic evidence of PDA underwent an attempt of catheter closure at a median age of 2.1 years and median weight of 10.7 kg. The median Qp/Qs ratio was 2.3, the median length of the PDA was 6.7 mm and the median diameter of the PDA at its narrowest point (usually the pulmonic end) was 3.8 mm. Immediately after closure and by angiography, the PDA was completely closed in 177/311 patients (56%) and within 24 hr the complete closure rate increased to 76% (235/308). Complications were encountered in 15 patients, including 1 major complication due to device embolization and subsequent death, 6 moderate complications, and 8 minor complications. The median fluoroscopy time was 12 min and the median total procedure time was 70 min. One hundred fourteen patients reached the 6-month follow-up. Color Doppler echocardiography demonstrated complete closure in 109 patients (94.6%). Thirty-eight patients reached the 1-year follow-up mark. There was complete closure in 100% of the patients as documented by color Doppler echocardiography. So far there has been no episodes of delayed device migration, endocarditis, thromboembolism, and wire fracture or device disruption. We conclude that the ADO is safe and effective in most patients with PDA up to a diameter of 10.6 mm. Further clinical trials are underway to assess its long-term safety and efficacy.