Isolation of the right subclavian artery from the aortic arch is a rare malformation. When isolated, the artery originates from the right pulmonary artery via a right-sided arterial duct, which may be patent or closed at the time of presentation. Intracardiac or other anomalies of the great vessels are commonly associated with this lesion. We present a case of isolation of the right subclavian artery which was initially diagnosed as persistent patency of a left-sided arterial duct. Surgical correction was eventually achieved by disconnecting the right subclavian artery from the right pulmonary artery and translocating it to the ascending aorta.