Ramires agrees new five-year Chelsea deal
"I am very happy with the support I have playing for this club," he told the London team's website.
Ramires, who originally signed a four-year deal when he joined from Benfica in August 2010, made his 50th Premier League appearance in the 1-0 defeat at West Bromwich Albion at the weekend.
Saturday's defeat proved the last game for manager Andre Villas-Boas who was sacked a day later.
His number two Roberto Di Matteo has been put in charge of fifth-placed Chelsea until the end of the season.