Wilson, who earned $480,000 in 2009, was third in the league with 38 saves last year. An All-Star in 2008, the hard-throwing Wilson lowered his ERA almost two runs in 2009 to 2.74. He finished second in the league with 60 games completed.
"We're very proud of Brian, from the beginning when he was drafted to developing in our system," Giants vice president of baseball operations Bobby Evans said in a phone interview. "He's done a great job and become such a meaningful part of our organization. He's been an important part of this ballclub."
Wilson has established himself as a reliable ninth-inning option for a club that had lacked such a late-game presence since the days of Robb Nen.
When the sides exchanged arbitration proposals, Wilson asked for $4,875,000 and the Giants submitted a $4 million offer.
Information from The Associated Press was used in this report.