This film's story is set in Hamburg. Source novel author John le Carré worked for British intelligence's MI5 and MI6 during the 1950s and 1960s and worked in both Berlin and Hamburg. Le Carré was in Berlin when the Berlin Wall was being constructed and has worked as both a consul and an agent in Hamburg.
Producer Stephen Cornwell said of the film's story: "One of the interesting things about A Most Wanted Man (2014) is that it doesn't really have an antagonist. It has lots of people who all believe they are doing the right thing but their reasons are all different. They come into conflict around one central objective, which is the most wanted man who they all see from a different perspective and want for different reasons."
Actor Philip Seymour Hoffman worked with screenwriter Andrew Bovell on his characterization of Gunther Bachmann, a character for whom he came to have a great empathy. Hoffman said: "This movie is about a lot of things including, obviously, how countries deal with terrorism. But it's also about a man who keeps doing the same thing and getting the same result. You get the feeling he can't stop. He really feels like he's trying to do the right thing and I think, actually, he is. But the world isn't going along with his way of taking care of the bad guys of the planet. I was just so taken with his tunnel vision. He just thought 'It's going to work this time and they're going to see that I know, that I actually know'. That's a hard way to live, to be someone who thinks, 'if they could just see what I see, they'll get it'. But they never let him get there and he keeps going there. He suffers."
Philip Seymour Hoffman died in New York of mixed-drug intoxication at age 46, a week after the film premiered at the Sundance Film Festival.
Anton Corbijn: Can be seen in a small cameo of about one second. During a press conference shown on a TV screen, he sits next to Homayon Ershadi (Abdullah).