In January 1902 at the Vienna Medical Society Meeting, the surgeon Emerich Ullmann reported the first case of renal autotransplantation performed in the neck of a dog. In the same year, he presented the first xenotransplantation of the kidney (a goat with a dog's kidney). These publications immediately had a great impact on the medical word. After his failed attempt to transplant a pig's kidney into a young uraemic woman he stopped his research in this field in order to devote himself to other lines of surgical research. However, his idea survived him, because, nowadays, nearly 100 years later, pigs appear to be the most suitable donors for human renal xenotransplantation. Ullmann was born in Pécs, Hungary, on February 23, 1861. After a distinguished undergraduate career in 1878 his father (being also a medical doctor) sent him to study medicine at the world-famous Vienna Medical School. He graduated in 1884 and was immediately invited to the Surgical Department where Billroth worked. Next year, because of his interest in bacteriology he visited Pasteur in Paris and successfully volunteered to serve as a healthy subject to prove the effectiveness of Pasteur's antisera against rabies. Although Ullmann did not succeed in doing a human transplantation he gave birth to the era of the organ transplantation, stimulated vascular surgery and the development of transplantation immunology.