Jacques Borlée was a sprinter, specializing in 100m, 200m and 400m, winning eight Belgian titles in total. He was Belgian champion over 100m in 1981 and 1983, Belgian champion over 200m in 1979, 1981, 1983 and 1984, Belgian champion over 400m in 1982, and Belgian champion over 400m hurdles in 1977. In 1983, he won a silver medal at the 1983 European Athletics Indoor Championships in Budapest over 200m. In 1980, he competed at the 1980 Summer Olympics in Moscow, reaching the quarterfinals of the 400 meters. At the 1978 European Athletics Championships in Prague he ended fifth as part of the 4 × 400 m relay team. At the 1982 European Athletics Championships in Athens, he ended fifth in his first round race over 400m.