After winning the Argentinian league with San Lorenzo, Ledesma was signed by the Greek champions Olympiacos CFP, for roughly €1,800,000 giving him an opportunity to play in the Greek league and the UEFA Champions League. After one year with Olympiacos, he was loaned back to San Lorenzo for one season in August 2008.
On July 13, 2010, Ledesma returned to Colón on a free transfer.
National team
He made his national team debut against Chile, 18 April 2007. He was called up to a friendly against Norway on 22 August 2007. He made his 3rd appearance for Argentina against Australia on 11 September.