Largely unknown before 2004, she kick started the season by clearing 2.04 metres and winning the World Indoor Championships.

When the outdoor season started she won the SPAR European Cup with the same result, improving her personal best from 1.97 (achieved in 2002).

She finished fifth in the 2006 European Athletics Championships, failing to clear 2.00 m. At the 2008 Beijing Summer Olympics, Slesarenko finished fourth in the women's high jump with a jump of 2.01 meters, failing to clear 2.03 meters after three tries.

[3] However, in 2016 both she and her compatriot, bronze-medalist Anna Chicherova, were disqualified from this event after failing a retest of drug samples from Beijing.

[4][5] Slesarenko retired in 2014 after a successful career,[6] but in 2022 she was further disqualified for doping and her results were cancelled from 2008 onward, although she retained her 2004 Olympic gold medal.