In Seoul in 1988, Tanni represented Great Britain and won her first Paralympic medal, the 400m bronze. Spinal surgery forced Tanni to take a year away from the track and incredibly, at the 1992 Barcelona Paralympics, she stormed to victory taking four gold medals in the 100, 200, 400 and 800 metres. The same year, she won her first of six London Wheelchair Marathons.
Tanni won the 800 metres gold in the 1996 Atlanta Paralympics along with three silver medals in the 100, 200 and 400 metres. At the 2000 Sydney Paralympics, 31 year old Tanni returned with a vengeance, striking gold a fabulous four times in the 100, 200, 400 and 800 metres. In Athens 2004, aged 35, she takes first place in the 100 and 400 metres bringing her Paralympic gold medal tally to an astonishing eleven.