The new deal will keep Poli at the club until the summer of 2014.
Poli has been linked with a move to Manchester City.
“I am very happy to have extended my deal. It’s an honour and what I wanted,” he told the club’s official website.
“Sampdoria is the club where I made my Serie A debut and a team that has allowed me to develop and enjoy plenty of satisfaction. I want to thank everyone and the coach for such a great opportunity.”
