Jean Mohr was born in Geneva, Switzerland in 1925. He earned a degree in "sciences commerciales" in 1948 and began work at an advertising agency. In 1950, while travelling with the Red Cross to the Middle East, he discovered photography. After briefly studying painting in Paris, Mr Mohr moved back to Geneva in 1952 and worked as a freelance photojournalist. His work was published in several papers and magazines, and he received assignments from the International Labour Organization, the United Nations High Commissioner for Refugees, the Red Cross, and UNESCO, among other international organizations.
In 1978, Mr Mohr began working with the writer John Berger, a collaboration that would lead to a series of publications and conferences on the relationship between word and image. In 1984, he received the Prize for Contemporary Photography from the Musée de l'Elysée in Lausanne and in 1988, the city of Geneva Prize for Plastic Arts.
Between 1960 and 1974, Mr Mohr produced a number of photo stories for WHO. He travelled to all of the WHO regions and his work appeared often in the World Health magazine.