Mimoun did not compete in 1957 but returned in 1958 with a runner-up finish behind Stan Eldon in the individual race at the International Cross Country Championships and his first national marathon title. He placed seventh in the 10,000-meter event at the 1958 European Athletics Championships. In 1959 he came sixth in the individual race at the International Cross Country Championships, and won national titles in the marathon and cross country. As he neared his forties, his athletic powers began to decline. Although he continued to compete, he did not win a national title on grass or the track after 1959. Four further outings from 1960 to 1964