Born in 1891 he attended the medical faculty of Moscow University and then joined the Russian Army in 1914, being wounded three times, on one occasion suffering traumatic paraplegia for nine months. After the October revolution of 1917 Yudin worked at the Zakharino Hospital, interesting himself in particular in the study of extensive thoracoplasty for chronic empyema. For this work he was made a member of the Russian Surgical Association. In 1922 he went to the Industrial Institute at Serpouhoff investigating problems of regional and local anaesthesia and producing a monograph on spinal anaesthesia. In 1926 he visited the United States, going to the Mayo Clinic and the clinics of Crile, Cushing and Babcock. In 1928 he was appointed to the Sklifassovsky Institute in Moscow, the most important surgical centre in Russia. In 1932 he visited Barcelona, Paris and London, and it was at the Middlesex Hospital that he met Sir Gordon Gordon-Taylor. Yudin took particular interest in the work of Marriott and Kekwick on drip transfusion, having himself published a book on *The Transfusion of Corpse Blood* at about this time; subsequently he invited Kekwick to visit him in Moscow. He was unique in being the only Russian surgeon to visit clinics outside his own country and was undoubtedly the outstanding Russian surgeon of his day. Early in 1942 he had a coronary thrombosis and, while in hospital, wrote a treatise on the management of fractures due to gunshot wounds, but by June 1942 he had recovered and was appointed consulting surgeon to the Red Army. In 1943 a small Anglo-American military mission headed by Sir Gordon Gordon-Taylor and Elliott Cutler visited him in Moscow, and at this time he had performed over five thousand gastric operations, including 281 gastro-duodenal resections for bleeding peptic ulcer and eighty-nine cases of oesophagoplasty by a special technique of his own. A dynamic personality he was adored by his assistants and was a fervid patriot, a writer, a poet and a man of wide culture. He died of a coronary thrombosis in Moscow on 14 June 1954 aged 63.