Retallick said he still had room to improve, and the ambition to play in back-to-back Rugby World Cups was a big motivator to stay put.
"I am only young and still have plenty to learn about the game," the 23 year-old, 2.04m lock said.
"There is a lot I want to achieve and I firmly believe that New Zealand is the best place for me to grow my game and accomplish my goals.
"I have access to the best coaches in the world, play in teams with great lads and great environments and am really enjoying my footy."
Chiefs chief executive Andrew Flexman was also pleased that Retallick had shown such long-term commitment to his club and the All Blacks jersey.
"Brodie is a huge part of the Chiefs and having a player of Brodie's calibre locked in for another four years gives our forward pack real solidity and continuity," Flexman said.
"He represents everything that is highly valued by the Chiefs.
"Brodie is a hard-working, top bloke who is passionate about rugby and the region so this is great news for our fans, sponsors and stakeholders alike," he said.
Retallick has played 56 matches for the Chiefs and 36 tests.