The word 'fuck' is said at least 259 times through the series, averaging at over 10 'fucks' per episode, or 1 'fuck' every 2.2 minutes.
Revy was modeled after Lara Croft of the Tomb Raider franchise.
Dutch is a Vietnam war veteran and makes frequent references to battles and tactics used in the war.
Benny's character is based on the life of Jake Adelstein, an American journalist and writer who has spent much of his career in Japan covering vice and organized crime. Mr. Chang is based on characters commonly played by 'Chow Yun-Fat' in films by John Woo, such as Jong in The Killer and especially Mark Gor in A Better Tomorrow (1986), as both Chang and Gor are members of the Hong Kong Triads, wield dual pistols and don similar attire.
In an interview with Otaku USA, Rei Hiroe stated that Black Lagoon was inspired by James Ellroy, John Woo, Quentin Tarantino and Stephen King, as well as hearing about actual piracy cases in the East China Sea in the 1990s.