He lived and worked in France beginning in 1920. His style was somewhat akin to Impressionism. A figurative painter of landscapes, he had exhibitions starting in 1930. He is known for his frequent depiction of horses and dreamy beach scenes. Dutch critics admired his work as did French ones, who often compared him to Odilon Redon. "[Klein] starts from a dream of colors from which the motif gradually takes shape. Notwithstanding he still reverts to reality with this, albeit a dreamed up reality," one review concluded. On his 80th birthday, the Van Gogh Museum in Amsterdam held a retrospective of his work. In recent years, there has been renewed interest in his paintings, leading to a spike in prices.
Fred Klein was married first to the painter Marie Raymond, the mother of Yves, and then to the painter Ursula Bardsley. The first husband of Ursula Bardsley was the first Director of the mondial islamic ligue (Râbitat al–‘âlam al-islâmî)in Paris.