Carl-Gustav Groth was a pioneering transplant surgeon at the Karolinska Institute, Sweden. He was born in Helsinki, Finland, on 15 October 1933. His father, Carl-Johan Groth, was a businessman; his mother, Margareta Groth née Sonkin, was a housewife. Carl-Gustav's elder brother, Carl-Johan, went on to become a high-ranking diplomat and the Swedish ambassador of Denmark. Carl-Gustav moved with his parents to Stockholm at the age of 11 during the Second World War. He went to school in Stockholm and studied at the Karolinska Institute, where he gained his MD in 1961. He trained in surgery at the Serafimer Hospital in Stockholm, and in 1965 was awarded a PhD for his work on rheology in trauma. Groth then received a post-doctoral research fellowship from the National Institutes of Health, USA, to study transplantation surgery at the University of Colorado from 1966 to 1968. His knowledge of blood flow proved to be extremely useful when Thomas E Starzl, together with Groth, performed the first successful liver transplantation in man in 1967. Groth returned to Colorado in 1971 as an associate professor of surgery. In 1972 he returned to Sweden and became an associate professor at the Karolinska Institute and chief of transplantation surgery at the new teaching hospital, Huddinge Hospital. Here he built up an excellent, perfectly organised, transplantation ward. In 1983 he was made professor of surgery. Groth performed the first pancreas transplantation in Sweden 1974, and pancreas transplantation became one of his main research and clinical interests. He pioneered bone marrow transplantation in Sweden 1975 and paved the way for establishing hematopoietic stem cell transplantation. Groth also performed the first liver transplantation in Sweden in 1984 and the first pancreatic islet cell transplantation in 1996. He was the first in the world to cure Gaucher disease by bone marrow transplantation and to use porcine pancreatic islet transplants in humans. He was a skilled writer and wrote more than 600 scientific publications, which have been cited more than 17,000 times. He was a member of the Nobel Assembly from 1986 to 1999 and chairman in 1998. He was president of the Transplantation Society from 2001 to 2002. Groth was presented with many honours, including the Medawar Prize (in 2006), His Majesty the King of Sweden's medal (in 1998), the American Society of Transplant Surgeons pioneer award and the Maharshi Sushruta Award. A transplantation ward has been named after him at a clinic in Ahmedabad, India, and a Carl-Gustav Groth lecture, prize in transplantation research and a conference hall have also been established in his honour. For those of us who worked with Carl-Gustav, he was an inspiring mentor, teacher, example, pioneer and dear friend. He cared for his family and his employees. He had a great sense of humour and read a great deal. He was extremely good company. One of his major interests was offshore sail racing. On his sailboat he gathered many of his friends and colleagues. I had the privilege to serve as crew member on his yacht *Supernova*. Among other things, Groth won the Baltic Race and many other offshore races. In 1959, he married Birgit Hammargren, a Montessori teacher. They had three children. The oldest son, Johan, works in IT technology. Magnus, their second son, is an economist. Their daughter Helena is also an economist and works as a copywriter. There are nine grandchildren. In 2008, Carl-Gustav underwent a coronary bypass operation. Two stents were also later inserted. He was on anticoagulation medication and had problems with haemorrhages. He also fell and fractured his pelvis. With time, he became increasingly frail, but could occasionally keep up a scientific discussion on a high level. In the end, he had a calicii infection and during this he fell asleep on 16 February 2014 and never woke up. He was 80.