Strikeforce: Shamrock vs. Diaz was a mixed martial arts event held by Strikeforce on April 11, 2009 at the HP Pavilion in San Jose, California. It was the first event promoted by Strikeforce after their acquisition of assets from the defunct EliteXC promotion through its parent company ProElite. It aired on the Showtime cable network and online through Strikeforce All Access.Gus Johnson, Mauro Ranallo and Pat Miletich were commentating during the broadcast and Jimmy Lennon Jr. was the ring announcer. The official attendance was announced to be 14,409.
Gilbert Melendez
Rodrigo Damm
Nick Diaz
Frank Shamrock
Scott Smith
Benji Radach
Cristiane Justino
Hitomi Akano
Brett Rogers
Ron Humphrey
Luke Rockhold
Buck Meredith
Eric Lawson
Waylon Kennell
Raul Castillo
Brandon Michaels
James Terry
Zak Bucia
Shingo Kohara
Jeremy Tavares