"Factotum," due in theaters Friday, is based on Bukowski's 1975 novel.
Dillon's character, Hank Chinaski, is widely accepted as a fictionalized version of the late writer.
"I didn't want to get involved in an impersonation of Bukowski and the filmmakers were like, 'Well, we don't want that either because it's Henry Chinaski, his alter-ego!'" Dillon told UPI in New York recently. "That actually gave me a little latitude and I felt more comfortable."
The Oscar-nominated "Crash" actor, who has long been a fan of Bukowski's work, said he was surprised when director Bent Hamer asked him to play Chinaski in "Factotum."
"My first reaction was like, 'Are you sure you have the right guy?'" the 42-year-old actor said, admitting he pictured the character much older.
"They said, 'You'd really be a good Chinaski, and, by the way, you are at the right age now' ... I was like, 'Gee, thanks a lot!'"