Don Cheadle only had a couple of weeks to prepare for the role of Sammy Davis Jr.. He learned to sing, tap dance, play drums, play trumpet and twirl six-shooter pistols like Davis did. He took tap dance lessons from Savion Glover.

Chazz Palminteri was considered for the role of Dean Martin.

Don Cheadle was uncomfortable with the scenes in which Sammy Davis Jr. laughs at racial jokes made at his expense. Cheadle asked Salem to include the scene in which Davis explains to May Britt that he endures the jokes so that future black entertainers will not have to do so.

Ray Liotta, along with the usual preparation of watching Frank Sinatra's performances and films, also watched Nixon (1995) starring Anthony Hopkins. Liotta was inspired by Hopkins because Hopkins did not resemble Richard Nixon but convincingly portrayed him.

Frank Sinatra died a few months prior.

The scene in which the Rat Pack perform "High Hopes" was the first scene filmed.

William Petersen portrays John F. Kennedy in "The Rat Pack" and also JFK's father Joseph P. Kennedy in "The Kennedy's of Massachussettes".

This was Dan O'Herlihy's final acting role before his death on February 17, 2005 at the age of 85.

Barbara Niven gained 20 pounds to play Marilyn Monroe.

Ray Liotta was previously offered the role of Frank Sinatra in Sinatra (1992) but he turned it down.

Don Cheadle who plays Sammy Davis appeared in the remake of a Sammy Davis film Ocean's Eleven.

Don Cheadle would go on to appear in the Ocean's 11 (1960) remake, Ocean's Eleven (2001).

'Tommy Davidson' auditioned for the role of Sammy Davis Jr.