Birol Ünel had not been in military service in Turkey and therefore could not travel to Turkey without being arrested. However, as they say on DVD, at the last minute Turkish parliament decided on an amnesty, so he could return to his home country for the first time after 10 years and finish the movie.
Sibel Kekilli, who has a very distinctive nose in the film, spent the money she earned from "Head-On" getting a nose job.
The first German film in 17 years to win the Golden Bear at the Berlin Film Festival.
In the opening scenes, where Cahit appears to be completely drunk, Birol Ünel isn't acting. He really was completely drunk, having been drinking solidly whilst waiting hours for the scene to be set up.