Tadeusz Zajdel was one of the early leading Polish ski jumpers. His first major success was in the 1922 Polish Junior Championships when he won the cross-country race, and the following year he won the junior ski jumping title. His greatest achievement at the senior championships was his ski jumping second place finish in 1924, and the following year, he competed in both jumping and 18 km cross-country at the 1925 World Championships, but with little success finishing 38th and 82nd respectively. His jump of 40.5 m on the hill in Zakopane in 1926 set a new Polish record. During the race of the military ski patrol in St. Moritz in 1928, where he was a member of the Polish squad, his ski broke which resulted in the Polish team dropping down the overall standings. Shortly after the end of his sporting career, he took up painting.