[3] Gueorgiou has won more than 20 gold medals in international competitions, including the World Orienteering Championships (WOC) middle distance event a record eight times: 2003–2005, 2007–2009, 2011 and 2017.

[6] Running for Fédération Française de Course d'Orientation, Gueorgiou made his debut at the 1995 Junior World Orienteering Championships in Denmark at the age of 16, coming 60th in the Short distance and 10th in the relay.

Gueorgiou made his senior international debut at the 1997 World Orienteering Championships in Grimstad, Norway, at the age of 18.

in 2001 Gueorgiou came 19th in the Short distance after a near perfect run, which led him to make changes to his technique that would eventually lead him to multiple world championship victories.

Gueorgiou announced his retirement from international competition after the 2017 World Orienteering Championships in Estonia, where he won his final gold medal in the Middle Distance.

[10][11] At WOC 2009 in Miskolc, Hungary, during the last leg of the relay race Gueorgiou, Anders Nordberg (Norway), and Michal Smola (Czech Republic) were close behind the lead runner, Martin Johansson (Sweden), when Johansson suffered a 12 cm deep penetrating trauma from a stick in his right thigh.

[8] Gueorgiou is noted for his incredible map- reading, and is frequently named as "The King of Middle Distance" for his multiple victories at world championships.