Salonen received his PhD in 1950. From 1949 to 1978 he held the position of associate professor of Assyrian and Semitic Philology at the University of Helsinki.[3] His research interests focused on the material culture and everyday life of Mesopotamia, such as its watercraft, vehicles and doors; a large part of his work consists of thematic glossaries of specialized terminology. He published the first Finnish translation of the Epic of Gilgamesh in 1943.[2] He was also interested in the history of Persia and ancient Egypt, and had a command of Arabic. In 1957, together with Jussi Aro, he published the first Finnish translation of the Quran.[2]