After serving at the Royal Norwegian Navy he became a family doctor at the University of Trondheim from 1983 to 1986.
After a year of training in occupational medicine he joined the Norwegian Cancer Society as a research fellow from 1987-90.
In 1996, he became chair of the Epidemiology Department at the Norwegian University of Science and Technology Medical School, a post he still holds.
[1] From 1997–2002 he was adjunct lecturer in cancer epidemiology at the Harvard School of Public Health in Boston, US.
Lars Vatten is a Member of The Royal Norwegian Society of Sciences and Letters.