Børge Mogensen initially worked in the office of Kaare Klint. From his time there Mogensen fostered a deep commitment to producing classical, simple and highly functional furniture. He also became interested in researching people and their trends in order to develop domestic objects that were customized to their specific use.
Mogensen was a prolific furniture designer, exhibiting almost every year at the Copenhagen Cabinetmaker's Guild Exhibitions, and was the Head of Furniture Design during the 1940's for the Danish Cooperative Wholesale Society. By the 1950’s Mogensen had re-embraced a more straightforward functionalism. He designed a set of simple, sturdy and modest furniture for a seaside cottage in 1959, a very traditional oak table and chair set in 1960 and a set in pine to furnish a "husband's study" in 1962. Mogensen also collaborated extensively with weaver Lis Ahlmann on textile designs, and, after Klint's death in 1954, succeeded him as designer to the Museum of Decorative Arts in Copenhagen.