"It is very important for us to win something this season," said Gallas. "It will not be easy for us because every team wants to beat Arsenal but we are ready to fight them.
"When you start the season and start winning game by game, you believe in yourself and the squad.
Arsene Wenger's side will have one foot in the knockout stages of the Champions League if they defeat Slavia Prague tonight at the Emirates Stadium.
The Frenchman stressed how important it was for silverware after ending up empty handed last season.
"This season I don't know if we will win the Champions League or the Premier League but definitely we have to win something," he added. "If we can win them both that would be good.
"We play good football but I have said before you can play well and win nothing. Maybe we have to play not so good but we win. The more important is the victory."