Aleksander Rozmus started skiing while attending high school, participated in the Polish Championships for the first time in 1920, and the following year was the ski jumping champion, a victory he repeated in 1922. Between then and 1930, he added four more second places in jumping and one in Nordic combined. In 1923 he was the first Pole to jump more than 30 m. Throughout the 1920s he competed in the 1925, 1927 and 1929 World Championships but without placing better than 24th (1927 in Nordic combined). At the 1928 Winter Olympics, he set a new Polish ski jumping record with 56.5 m. Rozmus worked in Zakopane as a commercial employee until he joined the army in 1939, serving as a courier in World War II. Later he joined the Polish resistance and after his escape to France, the French resistance movement. After the war, he stayed in France and worked as a skiing instructor in Chamonix.