|Representing East Germany|
|1988 Seoul||400 m hurdles|
|1980 Sittard||400 m hurdles|
|1983 Helsinki||400 m hurdles|
|1983 Helsinki||4 × 400 m relay|
She won the bronze medal at the 1988 Summer Olympics in Seoul, in a career best time of 53.63 seconds. This ranks her third among German 400 m hurdlers, only behind Sabine Busch and Cornelia Ullrich.
She also won the 1981 IAAF World Cup event, took the silver medal in the hurdles at the 1980 World Championships in Athletics, won the bronze medal at the 1983 World Championships and finished sixth at the 1986 European Championships. At the 1983 World Championships she also won a gold medal in the 4 × 400 metres relay. Although it was Gesine Walther, Sabine Busch, Marita Koch and Dagmar Rübsam who ran in the final, Fiedler had run in the qualifying round.
Fiedler is 1.76 metres tall; during her active career she weighed 66 kg.
|1980||World Championships||Sittard, Netherlands||2nd||400 m hurdles||54.56|
|1981||European Cup||Zagreb, Yugoslavia||1st||400 m hurdles||54.90|
|World Cup||Rome, Italy||1st||400 m hurdles||54.82|
|1983||World Championships||Helsinki, Finland||3rd||400 m hurdles||54.55|
|1st||4 × 400 m relay||3:29.05 (heats)|
|European Cup||London,United Kingdom||1st||400 m hurdles||54.20|
|1986||Goodwill Games||Moscow, Soviet Union||3rd||400 m hurdles||54.80|
|European Championships||Stuttgart, Germany||6th||400 m hurdles||54.90|
|1988||Olympic Games||Seoul, South Korea||3rd||400 m hurdles||53.63|
| Women's 400m Hurdles Best Year Performance