"This isn't just. It's great Friday," Tatupu told Seahawks president Tim Ruskell upon finalizing the contract Friday.
"I'm going to end my career with the Seahawks."
The deal includes the final two years on the original contract he signed after being selected in the second round out of Southern California in 2005, plus six more years worth a potential $42 million.
Fletcher Smith, Tatupu's agent, said the deal includes about $18 million in guaranteed money from 2008 to 2010.
Tatupu was supposedly too slow and too short when he was the sixth linebacker taken in '05. Last season he became the second player in Seahawks' history to be named to the Pro Bowl in each of his first three years.
"I think I've exceeded a lot of people's expectations, but not my own," Tatupu said.