Randolph, who had a game high 25 points on Sunday as the Grizzlies beat the San Antonio Spurs for their maiden playoff victory, will earn $66 million over four years, according to local media reports.
"During a week that has seen the Grizzlies franchise take a significant step forward with its first-ever postseason victory, it is incredibly meaningful for this organization to be able to take another by ensuring that Zach Randolph will continue to play on Beale Street for many years to come," said Chris Wallace, Grizzlies general manager in a statement.
Randolph, traded to Memphis in 2009 from the Los Angeles Clippers, led his team with an average of 20.1 points per game and had a career-high and franchise-record 12.2 rebounds per game in 75 games this season.
Taken in the first round of the 2001 draft by the Portland Trail Blazers, Randolph has been one of the NBA's most consistent performers, averaging of 17.6 points, 9.2 rebounds and 1.7 assists in a 10-year career that has also included brief stints with New York Knicks and Los Angeles Clippers.
(Writing by Steve Keating in Toronto; Editing by Frank Pingue)