Ahead of their Group C opener against Japan, the midfielder concedes that defeat would hand a big advantage to every other team in a group which also includes Colombia and Greece.
"The most important thing will be decided in the first game. That will be very, very important," Toure told reporters.
"If we start well we will get massive, massive, massive confidence.
"But if we start slow or sloppy in the first game it will be tough for the rest because all the other teams in the group have experience and have been in World Cups for a couple of years, like Japan and Colombia."
Ivory Coast failed to reach the knockout stages in both of their previous World Cup appearances.