Czesław Zając was a member of the Polish Army from shortly after World War II and became an officer in the early 1950s, eventually rising to the rank of sergeant major. He served as a shooting instructor and transferred his skills to the realm of amateur sport, where he won 13 titles across two disciplines between 1955 and 1966 and set numerous national records. During that time, he represented Poland at the 1960 Rome Olympics, where he was seventh in the rapid-fire pistol, 25 metres, event. He had better luck in that event at the 1963 European Championships, where he won a bronze medal.