London and Brazil national team's defender extended his contract with his current club - now his contract with Arsenal is valid until 2009.
Brazilian, 28, joined the London team in 2002, after performing well in the Brazil national team, which won the World Cup that year.
During his career at Arsenal, Gilberto played a total of 120 matches and with the club, he managed to win the English Premier League in 2004, as well as the FA Cup in 2003 and 2005.
This season, with Patrick Vieira leaving, Gilberto became the senior player in Arsenal's midfield, as his partners on the field, Cesc Fabregas, are only 21 and 18 years old respectively.
"I am currently the oldest player in my position at the club, but that doesn't change anything. On the contrary, now even greater responsibility falls on my shoulders," Gilberto said.
"Cesc and Matthieu are still very young, but these players demonstrate such a level of play that allows us to have full confidence in them. Yes, of course, we will miss Patrick (Vieira), but I am completely convinced that even without him we are a great team, so we must continue to improve and move forward."