The surgeon and urologist Werner Forßmann (1904-1979) was awarded the Nobel Prize for Physiology or Medicine in 1956. At the time of the prize ceremony, several newspapers portrayed Forssmann as an unknown rural physician who suddenly had become an international star. Drawing on nominations and reports in the Nobel Prize Archive for Physiology or Medicine in Stockholm as well as correspondence from the private archive of the Forßmann family, this paper reconstructs why the Nobel Committee chose to award Forßmann. We show that Forssmann's work was appreciated in medical textbooks and that he enjoyed a relatively sound reputation in the international scientific community even before he became a Nobel Prize laureate. At a more general level, we use his example to explore some mechanisms of scientific recognition.