According to Werner Herzog, 2,400 cans of decaf coffee had to be used to make the water appear to be river water in the jail scene. They first attempted to use paint, but it proved to be toxic, then the production team used regular coffee, but the actor absorbed it through his skin.
Nicolas Cage claims that he was never under the influence of anything throughout filming, in contrast to Leaving Las Vegas (1995) in which he got genuinely drunk to play an alcoholic.
In a June 2008 interview with The Guardian, Abel Ferrara, who directed and co-wrote the original Bad Lieutenant (1992), said that finding out his movie was being remade was "a horrible feeling", "like when you get robbed", and that those involved in this remake "should all die in hell". He also wondered how Nicolas Cage "can even have the nerve to play Harvey Keitel", and called screenwriter William M. Finkelstein an idiot. Werner Herzog responded that he had never seen the original and had never heard of Ferrara. In 2018 at the Newcastle International Film Festival, Ferrara said that he had finally met Herzog years after the release of the remake and made peace with him, something Herzog had wanted to do since hearing about Ferrara's outrage. Herzog said in The Origins Podcast that their meeting ended up lasting three hours, most of which consisted of them laughing together.
The movie was originally set in New York but Nicolas Cage changed the setting to New Orleans to help them after the hurricane.
During filming Nicolas Cage asked the entire set for silence to make a declaration. Once the set had gone silent Cage pointed to Werner Herzog and proclaimed: "Finally, someone who knows what he is doing." This was in reference to Herzog's method of only filming camera set-ups that he intended to use in the final film as opposed to shooting extra set-ups that he might not even use in the final film.