Kiessling proved to be the final East German 1500 m champion in 1990, winning both indoors and out. Her international success continued that year as although she narrowly missed a medal at the 1990 European Athletics Indoor Championships, coming fourth behind Britain's Lorraine Baker, she the first and only major outdoor senior medal of her career at the 1990 European Athletics Championships – her 1500 m silver behind Snežana Pajkić meant the East German women featured in the top two of all track events from 100 metres up to 1500 m that year.