Kristiansen's designs are considered embodiments of Danish mid-twentieth/mid-century century furniture. He designed everything from writing desks, tables, sideboards, chairs, bar cabinets and TV-stands, mostly manufactured in ever-popular teak or rosewood. He trained as a cabinetmaker, graduating in 1948 and then went on to train under Kaare Klint at the Danish Academy of Fine Arts. In the 1950s, he opened his own design studio and entered into many successful collaborations. From 1966 to 1970, Kristiansen was the driving force behind the Scandinavian Furniture Fair.