The story line of the film was mostly improvised at the same time as the film was made. The original story treatment was written by Luigi Montefiori (aka George Eastman) and turned into a script by Mino Roli and Nico Ducci, but director Enzo G. Castellari didn't like what had been written by the latter two. Because of problems with the schedule, Castellari and actor Joshua Sinclair wrote the script for the next day every evening after filming of the day. Castellari was also open to suggestions from the cast and crew - Franco Nero has confirmed that he wrote some of his own dialogue.
Director Enzo G. Castellari has stated that out of all the films he has directed, this is his personal favorite.
Keoma is a Native Indian word that means "far away" and not "freedom" as it is often misinterpreted as.