Prat received a Doctor of Medicine degree from Madrid Medical School in 1970. Eight years later he was given a Doctor of Philosophy degree from the University of La Laguna.
Prat began his career as a resident at the New York Hospital of Cornell Medical College in 1973. Two years later he took the position of fellow at Memorial-Sloan Kettering Cancer Center.
In 1976, Jaime held the position of an instructor and assistant professor of pathology at Harvard Medical School at Massachusetts General Hospital. Then in 1981 he was appointed a director of pathology at Hospital Clínic of Barcelona.
Prat worked as a chair of pathology at University of Alicante from 1982 to 1986. In 1986, Jaime became a director of pathology at Hospital Sant Pau and professor at Autonomous University of Barcelona, where he worked until 2014. Nowadays he is an honorary professor at the same university and a senior consultant pathologist at Hospital Sant Pau.
Prat was a member of the American Cancer Society, the Royal College of Pathologists of Great Britain and faculty at the United States and Canadian Academy of Pathology in 1977-2004. He was a president of the Spanish Society of Pathology in 1993-1995, the European Board of Pathology from 1999 to 2004 and the International Society of Gynecologic Pathologists in 2007-2009.
He is also member of the World Health Organization Committee for Classification of Tumours of the Female Genital Tract and The International Federation of Obstetricians and Gynecologists, Committee on Gynecologic Oncology and American Joint Committee on Cancer.
Jaime Prat is married Serena Salomone. They have 3 children.