Mieczysław Kasprzycki played forward and defense in a long career lasting from 1929-52, during which time he played for multiple clubs. He started with Warta Poznań in 1929, but then skated for Vítkovice SSK (1930-35), Slavia Pravia (1935/36), Silesia (1935/36), Dab Katowice (1936-39), SKH Katowice (1935-39), Cracovia Kraków (1945-49), and KTY Krynica (1949-52), playing in both Poland and Czechoslovakia. Kasprzycki competed at the 1936 and 1948 Winter Olympics and then coached the Polish team at the 1952 Oslo Winter Olympics. He won five Polish league championships and was capped 35 times, appearing at the World Championships in 1937, 1939, and 1947.
During World War II, Kasprzycki was involved the Polish September Campaign, opposing the invasion of Poland, and also worked with the French underground. He was interned in Switzerland where he played hockey for Grasshopper Club Zürich.