The 2008 season saw Olga Kaniskina break her first world record in the 20 km Walk at the Russian Championships. She lowered the mark set by her compatriot Olimpiada Ivanova in August 2005. However, IAAF rules dictate that 3 official judges must be present at the race, for a world record to be ratified, making it unlikely that this record will be ratified, as there were not 3 judges present. She went on to set the 20 km championship record at the 2008 IAAF World Race Walking Cup held in Russia, finishing with a time of 1:25:42.
At the 2008 Olympics in Beijing, she broke the standing Olympic record for the fastest 20 km walk. She walked 20 km in 1:26:31 to beat the silver medalist by 36 seconds. The previous Olympic record was 1:29:05 set by Wang Liping in 2000 at the Olympic Games in Sydney, Australia.
She has been part of a training group coached by Viktor Chegin. More than a dozen members of that group have been suspended for doping violations. She did not return to defend her world championship on home soil similar to teammate Sergey Bakulin. It was later revealed that Bakulin was serving a previously unannounced doping suspension casting the suggestion that Kaniskina was doing the same. On January 20, 2015 Kaniskina was disqualified for 3 years and 2 months starting from 15 October 2012, and all her results between 15 July 2009 and 16 September 2009, as well as between 30 July 2011 and 8 November 2011 (which include two world championship golds) were annulled. The reason for the ban was anomalies in her biological passport. As a result of the doping ban she lost the job as head of the Olympic Victor Chegin Race Walking Training Center in Saransk, a position she got less than a month before. She followed Viktor Kolesnikov as head of the Center. Kolesnikov had also had to leave the job due to receiving a ban for an anti doping rule violation. On March 25, 2015, the IAAF filed an appeal with the Court of Arbitration in Lausanne, Switzerland, questioning the selective disqualification of the suspension periods of the six athletes involved, including the one for Kaniskina which currently allows her to keep her Olympic Silver Medal.