Career
He worked as a prosecutor in several important cases, including murder of Georgiy Gongadze and investigation of United Energy Systems of Ukraine. On March, 2006 he was elected as a people"s deputy of the Verkhovna Rada from Party of Regions list as №96 - but he was not a party member. Piskun was elected in parliament for Party of Regions again in 2007.
Piskun did not return to parliament after the 2012 Ukrainian parliamentary election after losing in single-member districts number 63 (first-past-the-post wins a parliament seat) located in Zhytomyr Oblast.
But in the election the party failed to clear the 5% election threshold (it got 311% of the votes) and thus Piskun was not elected into parliament. Piskun was only allowed to take part in the election after a court decision validated his entrance in the election, at first the Central Election Commission of Ukraine had refused to register him because in the last 5 years leading up to the election he had not lived in Ukraine.
Piskun is the only statesman in Ukraine whose dismissals by two Presidents have been overturned as unlawful by courts. The latest being an April 24, 2009 Kyiv Court of Appeals passing of a ruling saying President Yushchenko"s decree dated May 24, 2007, dismissing Sviatoslav Piskun from the post of the prosecutor general was unlawful, but Piskun did not submit any application for his reinstating on the post of Prosecutor General.
According to Piskun, his dismissal by President Yushchenko in October 2005 came because he stopped criminal proceedings against Tymoshenko and refused to drop proceedings against Petro Poroshenko.
He was criticized for closing the criminal case related to the United Energy Systems of Ukraine while serving under Viktor Yushchenko"s government in 2005. and dropping criminal cases regarding back-then Prime Minister Yulia Tymoshenko. On 30 March 2014 during the interview with Inter television channel he called for criminal prosecution of Ukrainian officials who are responsible for giving up Crimea to Russia.