She made her major senior Gymnastics debut at the 2003 World Championships in Anaheim, California, where she qualified to the Olympics with a score of 34.637.

[1] Bismpikou continued to compete in 2005, winning her first World Cup medal, silver on the balance beam, at the French International in 2005.

She began 2006 with a strong showing at the Maribor World Cup in Slovenia, where she was the gold medalist on beam and won two bronze medals on floor exercise and the uneven bars.

At the 2006 Europeans in Greece, she was a favourite to win a medal, but fell from the balance beam, handing the title to reigning Olympic Champion Cătălina Ponor.

This accomplishment won Bismpikou great praise in Greece and she was voted second place in the 2007 Female Greek Athlete of the year awards.