- July 25, 2008
Signed Bobby Brown as a free agent.
- August 14, 2008
Traded Metta World Peace, Patrick Ewing and Sean Singletary to the Houston Rockets for Donte Greene, Bobby Jackson and a 2009 1st round draft pick (Omri Casspi was later selected).
- September 22, 2008
Shareef Abdur-Rahim retired.
- January 10, 2009
Assigned Donte Green to the Reno Bighorns of the G-League.
- January 17, 2009
Recalled Donte Green from the Reno Bighorns of the G-League.
- February 17, 2009
Traded a 2015 2nd round draft pick to the Boston Celtics for Sam Cassell. (top-55 protected, did not convey)
- February 18, 2009
Traded Brad Miller and John Salmons to the Chicago Bulls for Drew Gooden, Andres Nocioni, Michael Ruffin and Cedric Simmons.
Traded Michael Ruffin to the Portland Trail Blazers for Ike Diogu.
- February 19, 2009
Purchased Will Solomon from the Toronto Raptors.
Traded Bobby Brown and Shelden Williams to the Minnesota Timberwolves for Calvin Booth and Rashad McCants.
- April 8, 2009
Waived Will Solomon.
- June 25, 2009
Drafted Tyreke Evans in the 1st round (4th pick) of the 2009 NBA Draft.
Drafted Omri Casspi in the 1st round (23rd pick) of the 2009 NBA Draft.
Drafted Jeff Ayres in the 2nd round (31st pick) of the 2009 NBA Draft.
Traded Jeff Ayres to the Portland Trail Blazers for Jon Brockman, Sergio Rodriguez and cash.