In 1939, Risom travelled to New York City to study American design. After a few difficult years finding work, Risom teamed with entrepreneur Hans Knoll. In 1942, they launched the Hans Knoll Furniture Company with 15 of the 20 pieces in the inaugural "600" line designed by Risom. These works included stools, armchairs, and lounges, made from cedar and surplus webbing—works which have since become design classics. In 1946, after serving in World War II, Risom decided to launch his own firm, Jens Risom Design (JRD), which he ran successfully for close to 30 years.

Through simple design and high-quality craftsmanship, Jens Risom significantly influenced American furniture design with his Danish approach. His furniture is displayed at the Museum of Modern Art and the Yale University Art Gallery. The iconic Risom Chair C140 was famously used in the White House, chosen by President Lyndon B. Johnson.