On the occasion of the hundredth anniversary of heart surgery, this article presents the remarkable work of the Russian scientist and surgeon Nikolai Terebinski. The medical world today remains largely unaware that he performed the first successful open valve operations. These experimental operations were conducted in Russia between 1926 and 1937 through the use of an extracorporeal circulation device known as the autojector. The experiments were reviewed based on Terebinski's original articles and experimental notes. Here we present the techniques and results of his landmark open valve operations on dogs. He performed more than 250 open valve operations, which were the first of their kind. In his attempt to create and then later correct tricuspid and mitral valve stenosis and insufficiency, Terebinski developed many principles of open heart surgery that are valid today. His work represents a milestone in the history of heart surgery.